Hey Benz and Ford proved you can get from place to place in a gasoline powered car. Why are people suggesting that there might be problems when multiplying that demonstration by millions?
The problem with this analogy is that we are already at the stage that multi-MW diesel engines are driving large ships, millions of gasoline powered cars are on the streets, and the suggested problem is "I doubt that diesel driven locomotives can work, because my cheap gasoline-powered lawn mover keeps crapping out".
There are literally millions of microinverters in operation (Germany alone has about 650000 officially registered "Balkonkraftwerk" installations, those are all microinverters, and there probably are quite a few who don't bother to register theirs), Germany alone has more than 15000 solar power plants with nominal net peak power of more than 500 kW, five of them with more than 100 MW, we have dozens of HVDC links on the planet that each feed GW of DC power into AC grids.
Just yesterday around noon, here in Germany, we had about 43 GW of solar power feeding into the grid, plus 4 GW of wind and 3 GW of hydro, at a total load of about 59 GW.
The problem is not that people are suggesting problems. There are very qualified people who are suggesting problems and who are advising governments on strategies to mitigate them or who are working on engineering solutions to them, and that is very valuable. But that doesn't mean that any suggestion of a possible problem by people who obviously haven't even bothered to get a clue as to roughly what the current state of the technology is is valuable. Nor does such behaviour suggest that they are actually genuinely concerned about real problems or about solving those real problems.
There are so many of the "rolling coal" types throwing shade at green energy that proponents of green energy assume that any word of caution or possible problems.
That certainly isn't true for me, and I don't think that it is true for many others either. I very much welcome suggestions of genuine potential problems that have so far been overlooked, because the best thing that can happen is that we are aware of those problem as early as possible, so we can mitigate them before we sink billions into stuff that doesn't work, or experience devastating problems because of a screwed up roll-out.
I don't assume that "any word of caution" is disingenuous, but I do conclude just that when it is obvious that the person speaking hasn't put in even the minimum amount of effort to have even the slightest clue what the current state of affairs is, and are spouting theories about supposed problems that are so blatantly obvious that obviously those people who are building renewable energy systems (believe it or not, those people tend to be electrical engineers) have thought of them decades ago, and have long since developed and deployed solutions for them, when the technology that supposedly is likely to be so very unreliable is in reality already deployed in thousands or millions of commercial products/installations, ...
I personally am quite sure that there will be problems, often not because of the technology but because of stupidity, oversight and procrastination. And I am equally sure that there will be problems that surprise all of us. It seems unlikely that any of this will prevent implementation, but the will be hiccups. Some quite disturbing to those affected.
It's just that that's exactly the thing that we've been hearing from nay-sayers for decades, all while renewable energy here in Germany has climbed from a percent or two (hydro power) of the electricity supply to regularly 80% plus. Always, the next few percent would make the grid collapse. Always, the proposed technology was imposible to build for some made-up "fundamental reason". Always, something catastrophic was going to happen any time now.
Politicians and utility companies over here even built a big-ish (3 MW) wind turbine back in the 80s with the explicit goal of demonstrating that it doesn't work. To quote from
Wikipedia:
The partners as well as the BMFT also had political motives connected with the project. Günther Klätte, management board member of RWE, stated during a general business meeting: "We require Growian [in the general sense of large wind turbines] as a proof of failure of concept", and he noted that "the Growian is a kind of pedagogical tool to convert the anti-nuclear energy crowd to the true faith".[6] A similar statement regarding the incurred financial burdens was reported of Minister of Finance and former Minister of Research Hans Matthöfer: "We know it won't do anything for us. But we do it to demonstrate to the wind energy advocates that it doesn't work."[6] After the Green Party had derided the installation as the electricity provider's "fig leaf" on the occasion of groundbreaking in May 1981, the RWE took internal measures to make sure that publicly a position of open-mindedness towards alternative energy production was emphasized while public interest in wind energy was allayed.
Now, that project did indeed fail, for reasons. But also, the Danes at the same time were already successfully building similarly sized wind turbines. And nowadays, we obviously have 15 MW models working just fine. Even though that fundamentally can't actually work, I guess.
And note how all of that happened with zero giant catastrophic events.
Now, obviously, there have been problems along the way. Obviously, not every approach worked out. Obviously, there have been prototypes that were dead ends. Obviously, here and there, solar inverters or wind turbines went up in flames. Those things obviously have been learned from, resulting in a pretty mature technology by now.
So, yeah, there have been hiccups, of course there have been hiccups. But nothing remotely on the scale of being a problem for grid reliability. And with the emphasis on "have been", because much of the hiccups that people imagine are going to come are already in the past. And also, rarely, if ever, were the doomsday scenarios painted by nay-sayers in any way useful for improving the technology. What was useful were people actually conducting studies. People actualy modeling grids with varying contributions from various energy sources. People doing the actual work that was necessary to figure out stable control schemes. Not people shouting over and over some variation of "control systems can be unstable if improperly constructed" ... like that's a thing that engineers aren't aware of.