If XMR usage got big enough it would very much need layer 2 even more, the developers themselves acknowledge this and are upfront about it. These very basic computing problems that have been repeated ad nauseam for a decade now do not magically go away and are actually a lot worse for monero due to ring transactions being much heavier.

Are you really going to store a 2 TB blockchain that needs days of compute to initially confirm so you can transact with your friends privately? The first layer has insane amounts of PoW security baked in at this point, it's not for general consumption anymore.