This came up in conversation recently and I realized I don't actually know the answer. Age verification has gotten much stricter on reputable platforms which is genuinely a good thing.
Blocking and reporting features matter a lot. Platforms that take moderation seriously are worth the small effort to join. Use a Google Voice number instead of your real number when you're still getting to know someone.
Anonymous chat is mostly an illusion unless you're running through a trustworthy VPN and using a burner.