I've only had one pair, REI brand made by Komperdell, I think. I've never broken one, but I can imagine it happening. But, the flexible tent poles most tents use can be broken as well.

With some, but probably not all, tents that use trekking poles for support, you could use sticks or trees if necessary. Several times I've done that when I wanted to use my poles for day hiking from a base camp. Seems like the best idea would be to get the manufacturer's poles and carry them or not depending on whether you might want them on a particular trip.

Of course, if you have them, you're subject to the "take them just in case" syndrome