Coinbase acts like this because it was founded from day one to serve the US market, and everything that it has done has been to invest millions of dollars a year into complying with US law. Coinbase has only in the past couple months, started expanding internationally so they don't die immediately in case the US regulatory system decides to cannibalize them.
Binance acts like this because complying with US law is ridiculously expensive. Binance cares most about serving the remaining 95% of humanity that does not live in the US. Maybe seven years or so ago they really started shifting things around so their US services are expendable, and could be jettisoned at any moment if US regulators start biting.
Both are entirely reasonable strategies, and it's why I, as a US citizen, moved everything I had in Binanace away 7 or so years ago, and only ever do anything custodial with Coinbase. Back in the before times, I had accounts across multiple global exchanges so I could run arbitrage bots etc, but now it's basically Coinbase or nothing when it comes to custodial exchanges.
That’s the strategy they explicitly chose. Probably because of the founder’s preference or vision. They wanted to position themselves as the legal crypto exchange which is a great differentiation in that market.
