I would not trust a staking pool with a lot of coins. Anyway I don't think that this thread is about staking pools and they are not official. The only official staking pools were closed 2 months ago.
That is why I think there can be an appeal to many users, considering not everyone wants to throw tens of thousands of coins in there. In reality if you have
that many coins you could make a decent return solo staking in the first place, so I think
https://stakeunited.com is a good place for those smaller/medium investments for sure considering how much more efficient & bountiful it makes the returns.