We had a fairly large Susan in a 1m diameter pot for eight years and it was fine in our very sunny, south-facing Wiltshire garden (although we were forever watering it!). When we sold that house in 2018 we finally put it in the ground in our new garden (Wales) and it seemed to double in size in a year. By the time we moved again in 2024 it was massive, so I'd say the pot had restricted it, but nonetheless it did ok.
Currently we're struggling with a Magnolia Festirose Denudata we planted in the previous owner's - admittedly narrow - raised bed. We assumed there was no base to the bed when we dug the hole to plant it in late 2024 as we were able to dig a long way down, but despite flowering loads last year, this year it has just three buds. Now I can only assume the roots are being restricted somehow or possibly doesn't like our new coastal location 😥