Is there any privacy coin which can compete with Monero in terms of privacy?

[dkbit98]

Litecoin with new Mimblewimble addresses starting with mweb sounds like interesting privacy alternative for Monero.
However, there are few problems with this since it's still early days, not many wallets support mweb address format (I think only Litecoin core wallet), and not many people are using them yet.
I would love to see this mimblewimble getting implemented in Bitcoin.

Litecoin mweb explorer:
https://www.mwebexplorer.com/

[ABCbits]

It depends on which implementation you use. JoinMarket somewhat decentralized, but not easy to use. Meanwhile, decentralized aspect on Whirpool (available on Sparrow and Samourai Wallet) is very new feature.

I nerver tested those wallets.

Are those coinjoin more expensive than using a mixer?

TLDR: Usually it's cheaper.

For JoinMarket, it depends on fee set by maker.

One group of participants (called market makers) will always be available to take part in CoinJoins at any time. Other participants (called market takers) can create a CoinJoin at any time. The takers pay a fee which incentivizes the makers. A form of smart contract is created, meaning the private keys will never be broadcasted outside of your computer, resulting in virtually zero risk of loss (aside from malware or bugs). As a result of free-market forces the fees will eventually be next to nothing.

For Whirlpool, this documentation page state the fee depends on which pool you use, https://docs.samourai.io/whirlpool/basic-concepts. But it's probably written before decentralized Whirlpool exist where i haven't tried that feature.