There's been talk about decentralized CoinJoin for years, but in practice (like most decentralized market solutions), there is not much liquidity to adequately mix coins. But there are real world examples of CoinJoin being used (see
https://en.bitcoin.it/wiki/CoinJoin). Blockchain.info used to have a Shared Send feature (not as private as CoinJoin, because the outputs don't have the same value) but they unfortunately removed it a year or two ago.
I'm not aware of much effort to organize CoinJoins in Ethereum. I haven't even heard of a reputable mixer. There was a service called WeiMixer being advertised on the forum (centralized mixer), but I think it's a scam.
I've heard of CoinJoin too, but it seems like that went nowhere. TumbleBit (payment hub compatible with Bitcoin) has been really hyped a lot -- supposedly totally anonymous and does not require any major protocol change. Unfortunately, I haven't heard about much progress there. Stratis has released an experimental TumbleBit server as of July; I'm not sure how successful it is.
I see.
Seems that there is some sort of gap which could be filled in the future. I've not really heard much about the other projects you two mentioned, other then Weimixer, which is indeed a scam probably,
https://bitcointalk.org/index.php?topic=2164153.0(No activity for 6 days all of a sudden?)
Coinjoin "works", but just doesn't have the volume to work correctly, do i understand that correct?