I don't understand the integration with Strike at all.
Why not implement the tipping feature in a way that works with any wallet (including, but not limited to Strike)?
I can only assume it's something to do with Twitter being a US-based entity, maybe? The only way it makes sense to me for them to knowingly restrict usage to US and El Salvador is if some regulator/lawyer/other-red-tape-dispensing-bureaucrat has advised them to.
It's likely they don't to end up facing (likely baseless) accusations of aiding money laundering, so they're going down the route that involves at least some KYC/AML.