Actually i do not believe newer layer 1 chains will be able to compete. Many have tried and yet most alternative layer 1 chains still have way way lower TVL than Ethereum (and plenty of them incentivize dapp developers to build on them while Ethereum Foundation does not have to do that). I think layer 2 rollups will eventually take over the market from all these layer 1 Ethereum-killers.

I also believe DEX tokens are great to invest as long as they have decent volume on Ethereum. https://university.despace.io/list-of-the-best-decentralized-exchanges put some great guide on the top DEX-es to go with