But we can take help from CoinMarketCap, Coingecko to verify if the exchange website is real or not. Because there is always a real website link here.
Not all exchanges listed on cmc and coingecko are reputable, they are indeed real website but the chance of your funds getting locked in is higher than using those exchanges that can be seen on their top 20 exchanges based on volume. Always google the exchanges' review, either on reddit and here (bitcointalk) and other community forums, ignore those review sites since most of them are paid.
When we can count coingecko and CoinMarketCap as part of research maybe not a solid one... even a reputable exchange can still be having the issue of getting accused for stolen fund although most are due to negligence, it will be so hard to come to conclusion just have you've said extensive researchis required.
There can also be a rest of mind to choosing a non custodial wallet over an exchange wallet Although that also need research but there are reputable ones like Blue, sparrow and Electrum exchange ge could be done on sites like
https://exch.cx/ since they might not support auto inexchange (swap)like exchange wallets