These reasons are as fair as they get. Third parties aren’t the most trustworthy, and people who live in unsupported regions can’t really be helped. Having to buy vrc+(and thus, another subscription to worry about) for verification ASAP also does add some discouragement, since it’s being implied all users will be able to sooner or later once its beta testing is over. But at least that means one day this will be an issue of the past.
I genuinely wonder why asking for DOBs is something that’s just normalized across the board, even outside of worlds that aren’t 18+. Last week I randomly had a mod of a world I was in ask for mine seemingly unprompted since I hadn’t interacted with anyone yet, nor had I ever been asked my age in the instances I’ve joined. I told them my actual DOB, given that there’d be no use in lying because of my bio. They then replied with “Note taken…” in a pretty snarky tone, as if they were up to something, and walked away. Doesn’t help that seconds before that interaction, 2 other, regular users came up to me to ask a very inappropriate question, and then started laughing because my reluctance to answer immediately “[had] to [make me] a minor”. So somehow being under 18 makes someone more of a problem rather than their actions or intentions, according to that world. Nonetheless, I left the world without hesitation, not wanting to know what the mod team wanted to do with me. Along with being scared off vrc for a few days, I probably won’t be joining another instance of that world on my own accord for a good while, all because of those 30 seconds I had to experience. If the mod just pulled me away and informed me on whatever caused them to want my age, I think I would’ve been fine with that.