As I wrote, I think treatments can tend to over-dampen a room, at least to my preferences. Great for audio effects and shaping of the sound, but not for a more natural sound experience. IMO.
Agreed that over-damping is possible, that is why I enjoy the benefits of removal of some of the treatments that I had -- upon your useful suggestion, I might add. Yet while you can over-do things, you can also easily under-do them. Extremes go both ways.
Again, it will very much depend on the room, and it will often be a fine balance, also between competing things one wants to achieve, according to specific individual tastes. There are no hard and fast, rigid rules.