Depends on your needs, Jira has lots of features and plugins.
We're building Linear, focusing on speed and providing sane defaults that sense for software companies. The app offline first so all interactions are <100ms. Sprints, projects, roadmaps, multiple teams, GitHub/Gitlab/Sentry supported etc supported. Lot of YC startups and growth companies (100-300 engineers) use us.
We migrated away from Jira to YouTrack, which is quite flexible. Speed wise it's not too bad, could be snappier. But it is really flexible with full APIs. Jetbrains also has "Spaces" which is more simplified but has other toys.
Preferably with an emphasis on speed?