I find pretty much all container grown woody material purchased from retail nurseries to be root-bound. With grafted stock being some of the worst, there apparently being an idea present inside the production system that plants designated for use as root-stock have even less of a need to be kept potted on that those that aren't.

Part of the problem appears to be a belief that end consumers will balk at potted plants that have the correct proportion between tops and container sizes. So a lot of woody stock is under-potted before it even first arrives at garden centers. With it being typical for a percentage of the inventory present at retailers to blow over every time the wind comes up, due to it consisting of big tops in little pots.

Field grown stock is not free of this because it often has been grown in containers before being sized up in the ground.

Containerized materials, especially those in gallon sized pots, often have serious root problems as a result
of poor potting-up techniques. Potbound plants exhibit circling root systems, which if not corrected
become woodier and more troublesome the older they get. Eventually these circling root systems become
girdling roots, which can lead to the early death of otherwise healthy trees and shrubs. At transplant
time, a more aggressive approach to root preparation can discover potentially fatal root flaws. Circling
roots, J-hooked roots, knotted roots, and other misshapen roots can often be corrected by careful pruning.
In this manner it’s possible to remove those root problems before they threaten the survival of your shrub
or tree.

https://s3.wp.wsu.edu/uploads/sites/403/2015/03/fragile-roots.pdf

I'll probably find one or two in my yard that are like that before too many years pass.

Two common warning signs when shopping are roots having come up out of the soil near the base of the specimen and tops of finished plants still having stakes holding them up, well after these should no longer be needed.

In addition to containers being way too small to be holding all of the roots a healthy specimen will have produced, without them being in a very crowded (and misdirected) state.

With roots having emerged from drain holes being another red flag - the correct time to pot on is when outer roots are approaching container walls. Otherwise the next step is circling roots.

All that said the carcass shown here may perhaps have Armillaria rhizomorphs visible on it. Also dwarf Alberta spruce is of course prone to be sucked dry during hot weather by mites.

yeah reminds me of the extremely upsetting loss of my Fagus 'Rotundifolia' which was even older. Planted in 2008, dug up about 10 years later to find a bowling ball shaped root knot.

Well it was supposed to be rotund.

Haha...good one!

I'm not sure I'd qualify the nursery where I bought it as "big box," but it's close (it's a large regional nursery). I bought it in June when it was 40% off. I don't remember the size of the pot, but it certainly appears to have been too small! I remember being very scared to disturb any of the roots for fear of killing it.

I've done a 180 since then. I recently bought a bald cypress (a Monrovia plant maybe?) from a big box store, and hacked the root system to pieces. It died.

I tend to use the slicing with a spade method, wherein I am interrupting circling roots but not cutting everything back otherwise. And not taking the time to wash everything clean - but I often do shake a lot of the potting soil off. Because you never want to plant in a pocket of coarse material surrounded by finer textured soil, due to how this affects movement of water.

If there is a tight knot at the base of the stem you really can't do anything about that, except discard the specimen. I once threw out a $35 cypress cultivar because when I bare-rooted it at planting the entire root-stock was caught up in a braid like a double helix or a hair braid - there was no way the planted specimen was not going to topple later.

Maybe if consumers start taking such material back and griping about it to retailers word will eventually start to get back to producers. Imagine for instance if it was routine to offer new cars to the market with frozen engines or serious oil leaks, how would that go over?