Rough estimate. If you take the capacity of the three major coinjoin protocols and LN and compare them to Monero market cap it is something like ~15%.
Not to mention willing to wager there is more KYC Bitcoin because practically every CEX has it, while Monero is largely delisted aside from a few options.
Yes, Cashu/Fedimint is an improvement on custodial, but it is still custodial. Imo that is against a major pillar of Bitcoin to begin with.