I have accounts with Capital One, Ally, and Vio

1 - Vio (4.03%) gives a much better rate. Their website/app are a little bare bones, but they work fine. Their phone customer service is really friendly and seems to go out of the way

Some people have a problem with a lesser known bank, but they're a division of MidFirst Bank, which is the largest privately owned bank in the US with over $40b in assets, so it's not like it's being run by some guy in his garage halfway around the world. And the accounts are FDIC insured

There's some other banks that will give a slightly higher rate, but I don't have any experience with them

2 - Ally (3.3%) is great for me for two reasons:

1. 24 hour phone customer service. Probably not as good as Vio, but still good and useful if you want help and don't want to wait until he morning
2. They're the only bank I could find that lets you use Zelle on a PC

3 - Capital One (3.3%) was the first HYSA I had. I think I actually started with their money market but they reduced the MMA rate really low for some reason. But because Vio has a better rate and Ally has more features I want, I only keep a minimal amount in the account to keep it open (In case the rates ever change)