Layer 2 liquidity and tokens available

I am new to Ethereum L2s and looking at Arbitrum and Base to swap some tokens.

There does not seem to be a lot of choice out there on the available DEXs, even Uniseap and GMX. It looks like if I want to swap ETH for USDC or DAI or wrapped ether then I can. If I wanted a token with a smaller market cap like Illuvium do I need to make that exchange on mainnet.

Am I missing something? Or is this what Sol fanboys mean when they talk about Ethereum layer 2s splintering liquidity?