When mindlessly browsing Reddit, I found that I usually just jump directly to the comments, read a couple, and continue. Lemmy seems a bit more curated (read: smaller), and therefore it’s easier to actually engage in discussions, which leads me to read the article, think critically about it, and respond (if I have something to say) in the comments–bigger is not always better!
You mean the official Youtube app? Almost certainly not, Google isn’t going to add that kind of functionality since it would give users a way to avoid ads as well. The SponsorBlock Firefox addon also doesn’t natively support Firefox mobile unfortunately. You might able to combine Firefox mobile, the Tampermonkey addon (which does support Firefox mobile) and a userscript sponsor blocker to get the same effect. I tested this briefly just now and it does seem to work, but it’s not something I use every because most of my video watching is on desktop.