Because my focus is primarily on bonsai, I have an interest in making sure my younger trees increase their mass asap; and of course this can only occur when the tree, and particularly their root systems, are healthy. I often repot a tree not because it needs repotting in the immediate, but because it WILL need repotting before the next opportunity to do so comes around. Some young trees need repotting every year, while others need it every 2 or even 3 years in some cases. As trees get older, their growth slows and repotting is required less frequently.
No tree is immune to the impact of root congestion. Once the root/soil mass can be lifted from the pot intact, the tree is already paying a tax on growth, vitality, yields, and probably appearance. Also, once you get all the peat-based mix removed from the root mass and the plant is potted in something like the 5:1:1 or the gritty mix, repotting and especially repots subsequent to the first are much easier.
Growing requires a lot of compromise unless we happen to make it a high priority. Most of us can't or won't, so we do things that might not be the best for the plant, but suit how we have arranged our own priorities better. There is nothing wrong with that. I KNOW I can get twice the growth from plants if I put them in a medium that requires watering several times per day, but I don't want to be a slave to watering, so I compromise and use a medium that allows me watering intervals of up to 5 or 6 days. If I'm really pressed for time, I might skip a repotting I know is needed so I have time to repot another plant that is in more dire need of a repot. There is a price to be paid for the delay; but, if the plant languishes for another year with roots tighter than the plant would prefer, I know all will be well when I get to it at the appropriate time during the next growth cycle. The best 'tell' for whether or not the plant needs a repotting is to lift it from the pot to see if the root/soil mass remains intact.
Now, if you know the plant needs repotting but you don't want to do it or can't until next year, remove the bottom several inches of soil/roots from the root ball, then cut some vertical slits in the root mass and tease out the roots, then pot up a size/ This will not offer revitalization to the same degree as a full repot, but it will be better than simply allowing Mother Nature to side with the hidden flaw, because she always does.
Al
Q