My back is pretty awful so I use one at work - it's a sit/stand desk so I can alternate between sitting and standing. But I mostly use it standing and sit in meetings.
I do get tired sometimes but that's a good signal to go for a walk - something we should all be doing regularly anyway. I've had back problems for many years, one major surgery already and I've learned to take pain management seriously.
I've never found it hard to find opportunities to sit down. Sit in the car. Sit on the couch. Sit down to eat lunch usually. So my standy desk is brilliant for the times in between.
Just listen to your body and keep it moving when it needs to move.
And wear the right shoes - because the more you stand the more important it is to be standing on the right shoe as the correct base for the rest of your body and posture.