But then, doesn't (or didn't) Reddit -- also a US company -- allow Bitcoin and crypto tipping? Didn't they have a tipping bot that didn't even interact on-chain until you withdrew?
Not too sure. Generally, I try to avoid Reddit at all costs where possible. But a quick search seems to suggest they allow people to use their own third-party tipping bots, meaning Reddit don't handle the tips directly. I'm sure someone clever could create something like that for Twitter. Or perhaps someone already has? It looks like Reddit also experimented with native support for fiat tips by credit card payments via Stripe, but I don't think that went anywhere (I could be wrong, though).
There are independent tipping bots on Twitter (no KYC etc.) already, for Bitcoin and other cryptocurrencies.
for Bitcoin via Lightning.