Quite the opposite. They’re super fibrous and almost woody closer to the stalks. I use a saw to cut the roots off the cup just to salvage the lids of my buckets at least.
They do get very tender towards the ends of the root systems though. That being said you have to be super careful if you have to do a full water change midway in flower. You can damage them with the weight of themselves, and that will rot
These were about a month or so old. The heavy green roots are what really take hold. They ended up doubling in diameter.