I travel carry-on only including for work and have for 20 years since I started travelling. From experience you want soft sided with pockets, expandable, good quality wheels and a resilient fabric.

Soft sided with pockets is easier for travelling. You’ve got your pouch to pull your liquids pouch out of easily for security. It will also squish a bit if you need it too. Gives you easy access to things you might need before boarding or when you land. Hard shell suitcases are a pain in the butt, get dinged up easily and won’t squish and they’re inconvenient for getting stuff in and out. They’re expansion capabilities often suck as well.

I have a Samsonite Silhouette Sphere 2 21 Which has been worth every penny and I absolutely love it. Going on 9 years with it, with pretty regular travel for work and personal every year except for 2020-now. My work travel is just starting up again. Edit to add I believe this one might be discontinued now.