Guitar effects could be good for content. But if you have 100,000 subscribers (and average view count of 4k) to a show about old electronics, my gosh you could sell a whole 20 of them a year, lol.
I don't think you get more than single digit percentage of guitar players who watch a Fran video will buy one. And then how many guitar players out of those viewers? I think half her viewers have a soldering iron, and there are probably plenty more who might be interested in buying one (from her affiliate link, maybe?) just to participate.
I'm technically a guitar player, and I'm not interested to pay for Chinese PCBA salaries $60 bucks so that Fran can make $10. Also, I haven't played in a long time. I learned on electric a long time ago, but now I own an acoustic (which I bought in a mid life crisis, tuned it, put it on a stand. I think I might still have it; I might have actually tossed it without every playing it, lol).
3-5k for her content videos. 30k+ on her rant videos. I wonder how many of these 100K subs even own a soldering iron.