As far as I know, mixers aren't illegal. No government has declared it yet, but you can raise suspicion if you use a mixer to hide the origin of your funds. While there are legitimate uses for mixers, that doesn't mean a criminal won't use it to break the law. The main reason why governments are targeting mixers is because of privacy concerns. After all, they want to have a full scope of your entire financial life.

I'd try to avoid using a mixer regularly just in case. With many centralized mixers being shut down by the government, we should expect the worse in the long run. Only non-custodial mixers will survive due to the way they're designed. Who knows what the future holds for privacy on Bitcoin?