Best tool I've used so far in this field has been Linear. It's simple, and a great balance between opinionated and customisable. The UI is simple and snappy too. It's like a polar opposite of Jira.
I loathe Jira. People should be allowed to have that many fields on a screen, its ridiculous what is allowed. What sets linear apart from it?
I think what sets it apart from Jira is the balance between customisation and opinionated features I mentioned earlier. It will be useful a tool out of the box, but you can progressively enable a few extra features as your team grows.
I know on the surface it sounds a lot like Jira, but the execution is subtly better across the board. A lot of it is design/UX related too.
And lastly, it's very snappy. At previous job I had to wait seconds for between clicks for Jira to update. I don't know how that's considered okay by Atlassian (but I'm not sure if they upsell you "faster Jira" lol)
Another thing that stood out to me was their "Linear Method" posts https://linear.app/method