Bitcoin is supposed to be electronic cash. If I get cash from a casino, there's no way anyone can know, and nobody is going to refuse my cash for that reason. Ideally, Bitcoin should be treated the same.
Difference is that Bitcoin is digital and cash doesn't have history unless you mark them with special tracking devices, that is unrealistic for large amount of money.
Casino in cooperation with government could also spray invisible paint on bills to track their movement and alert authorities when you pay with them anywhere.
One way we could mitigate this is by using something like Bitcoin Notes, that could be used for Bitcoin offline cash payments.
There are indeed exchanges which rightly completely ignore any taint nonsense, such as Bisq and LocalCryptos, and coinjoin implementations such as JoinMarket. Perhaps we could also start a whitelist of online businesses such as gift card sellers which are known to pay no attention to taint and freely accept mixed or coinjoined coins, etc.
There are probably more exchanges and serveies that don't care about history of coins, but it would be impossible work collecting correct information about them for this whitelist.
One day exchange could accept any coins, tomorrow for whatever reason they could confiscate them, so I would give advantage to something that is really decentralized.