I think my iPad is an excellent thin client, however — but a Pro device should be more than just a thin client for me, imo.
Some things that would be a huge improvement for me:
1. Ability to do development locally
2. Virtualization (might circumvent the need to do local dev)
3. Install/build local applications
Apple seems determined to never allow anything outside of the App Store on i[Pad]OS, and with iPadOS being over four years old and still feeling like a giant iPhone, I don’t think I could recommend anyone should buy an iPad as a power user device.