I guess nothing is stopping it from becoming an L2 with sidechains (if that ever happens), but you would have to convince the current market to move over and that becomes increasingly difficult the longer time goes on.

So far, any L2s sacrifice some form of sovereignty for any privacy they provide. Monero doesn't. Liquid and Ecash are custodial. LN, in practice, is custodial or permissioned (LSPs and custodial wallets). And even using your own LN node offers less transactional privacy than Monero, anyway.

Monero is the largest crypto project behind only Bitcoin and Ethereum. It doesn't have a pre-mine or dev tax.