Major problem for a newly launched decentralised perpetual exchange is Liquidity. The problem extends if it is a spot and perps exchange, as cross-chain liquidity is a pain in the ass. You need coins from several chains to be escrowed by a third party and it costs lot of money to own the third party service provider for cross chain liquidity for spot deposits and withdrawals, just like hyperunit for Hyperliquid. They are handling the things well so far. Just look at Hyperliquid for how they are moving and you can create a dex but in reality it will be a lot difficult.