I won't evaluate whether or not your claim is true, but I waited 6 years to join reddit (and when I did, I immediately blocked and unsubscribed from all the main subreddits) and never made an account on YouTube. So I feel like I should be able to criticize platforms until they reach a stage that I want to use them, right?
One presumes that people are not in any way obligated to use garbage platforms they don't like to consume content they don't want in service of some higher commitment to a platform that does not exist but might emerge later under ideal circumstances. Rather it is typically the platform operator's job to manage the platform in a way that attracts content of interest, right?
And surely interesting content emerging is not a given. Voat is 4 years old (older than reddit and YouTube were when I started using them, at a point where most of their content was not fringe stuff). The front page is: Far-right politics, libertarian politics, some weird political thing about the french, a guy complaining about YouTube censorship, MAGA memes, MAGA memes, a picture of a cute cat cuddling with Nazis, an attempt to bandwagon someone who wrote a code of conduct, a meme about how George HW Bush is in hell because he doesn't support Trump, PewDiePie, Linux is over because of code of conduct, a meme about how there are only two genders, a meme about how liberals don't believe in fumigating ant hills because they're weak, a video about how George HW Bush is a piece of shit because he likes Israel, a post rhetorically asking why anyone is sad about George HW Bush dying, a Washington Times article about "illegal immigrants", a conservative article alleging Hollywood are all pedophiles, a nazi webcomic, an article about how Democrats stole all the California house seats, a post about how it would be good if someone lynched Emmanuel Macron and how that would be enjoyable, and a meme about how right-wingers should ironically wear burqas to own liberals while they are beating liberals up, a meme of Alexandria Ocasio-Cortez saying she's a stupid idiot (this is a "parody" -- not actually clear what it's a parody of, but whatever).
There are a couple I didn't copy-paste here because the titles have racial slurs in them and I couldn't figure out a way to summarize the content without repeating them. So I hope you'll provisionally yield that Voat has not yet grown beyond what you call the "startup platform" phase.
I guess it's possible that Voat is just about to turn the corner, but if I had to guess...