Is there anything monero can do that can't either 1) be achieved on main chain or 2) on a layer 2?
I've asked that question to multiple people who have never answered. Perhaps the good doctor can enlighten me.
Happy to have fun being dumb and rich.
Discussion
Short answer: Yes
Long answer:
2 main options for privacy with Bitcoin right now.
Coinjoins and Offchain methods.
1) Coinjoins offer inferior "privacy". Nothing is actually hidden with obfuscation. Also slower, tedious, and relatively expensive.
2) Offchain methods have potential to have great privacy, but so far come with major downsides usually giving up some sovereignty. You have to give up custody, ask permission, or require intermediaries.
Ecash, the only real contender to Monero's privacy, is custodial.
Many other downsides I could go into with the two methods above. But basically if you want strong default privacy, without giving up sovereignty, Monero is the only thing that fills that role right now.