You shouldn't be using mixer sites, they gain complete access to your funds and your transaction history. Coinjoin enabled wallets like
Wasabi allow you to create
anonymous on chain transactions without giving anyone else the chance to steal your BTC.
One thing I don't like about coinjoin is that they are very easily flagged by exchanges as coming from a "mixer" (like the terminology or hate it), so they will instantly freeze your account if you send any coins rom a coordinator there. So if exchanges or some payment processor is your destination then don't use that method.
Same problem as with some other, legacy mixers, such as Coinomize (unless you use max fees), Mixero, Jokermix, ... etc.
In general, the more fees you pay, he higher quality coins you will get.