It's a real tough thing. I've never done any YouTube, but I can imagine it's quite difficult to reach the point where it replaces 'conventional' income for sustainment.
I've been doing Youtube for 13 years, and 11 years full time now, and even after all that time the Youtube income alone would still not be enough for me to make this a full time living.
Well, I wouldn't be destitute over the US$50k US (+US$5K EEVblog2) income over the last year, but I could earn more as a professional engineer again, and that's what the wife would make me do
I only went full time and am very confortable now because I diversified my income streams (Youtube, Patreon, merch, product, website and forum advertising), and I made the decision early on to take on a bit of risk and buy my lab and storage unit instead of rent, and to pay it off as quickly as I could.
Also look at the other electronics Youtubers who are now bigger than my channel, like Electroboom and Great Scott, they would earn more Yotuube adsense revenue than me as they get more views, but they have to take in-video sponsorships to ultimately get a decent income. You have to do what you have to do to keep the dream job going. In my first year full time I had a side design consulting gig as the money wasn't quite there yet.