You can't find layer 1 blockchain tokens on DEX because L1 tokens usually list first there token on Centralized Exchange or build there own DEX in there blockchain.

But some blockchain project still builds on Ethereum and migrate later on to there mainnet so Uniswap is still your best chance to grab this kind of tokens early or Gate.i/Kucoin for CEX. Binance usually list L1 tokens that has already huge trading volume so you shouldn't scout there but rather on mid tier exchange like what I mention.