It's not like Bitcoin Mixers are too necessary for privacy. We can increase privacy following the methods you have shared. But, that's too much task to do. While Mixers take a few clicks only. When you could do it with a few clicks, why do you have to do that many transactions as an alternative? Mixers are banned in this forum, but they are still online. They are banned here does not mean we cannot use them.

Whoever used the mixers before and loved the idea will keep using them. Most of the forum users do not have dirty money to clean. I don't think forum users use Bitcoin mixers too much. The mixers do not expect huge traffic from the forum. They were here to build a reputation, so they could get trust from their users.