XMR *is* indisputably more anonymous than BTC. By default and by protocol. Amounts and addresses are never visible.
The receiver of XMR could be any user on the entire blockchain thanks to stealth addresses.
For senders, the weakest part, you could be one of 16 in a ring signature (~6% chance of finding sender), but every hop increases your anonymity exponentially. After only 2 hops from the original transaction you are already one in 4,096 or 00.02% chance of tracing you (16^3).
The Monero bug you are speaking of only affected sender privacy (amounts and addresses are always invisible) and was only an increase in probability of guessing sender. It was not deterministic.
Meanwhile, Bitcoin by default has 100% deterministic senders, while amounts and addresses are totally visible, working completely normally without any bugs!
All Bitcoin L2 privacy so far has been weaker and/or custodial and/or permissioned. Ecash is the best L2 privacy so far, but is custodial and the mints can print tokens secretly.
