I agree with @TelolettOm, checking their trading volume is another way to check if they are good to use or legit.
Another thing I can suggest is checking the community and reviews, check if there's something in the internet that complaining about their exchange or some reviews.
especially HITBTC which is a place to sell some airdrop coins and bounties that I have participated in.
Even HITBTC used to be quite popular before Binance, I also did some trading.
But for Latoken I don't use it often, just a few times.
Regarding the volume owned by the Exchange, it can indeed be the main benchmark that the Exchange is good and in great demand by users,
especially the community that is active for the Exchange.
Unfortunately, HITBTC is not crowded anymore and only has a volume of $190,091,263 and is in 339th place.
https://www.coingecko.com/en/exchanges/hitbtc