No, not all tires are equal. Not all black rubber is the same compound. If it's true in real car tires, it's true at the model scale as well. I've found that some brands and sizes of tires- example Lionel don' last as long as an MTH or Williams replacement tire. https://www.fournierrubber.com/blog/rubber-types/
Yes, it also "could be" your environment. Ozone, sunlight, oil, smoke fluid, track cleaner, and any other chemical present can effect the rubber differently again, depending on the compound of the rubber. Example I got a brand spanking new old stock Lionel Albert Hall engine that has never been run original packaging and was missing remote. The tires on it are a larger size rim (same as Hogwarts) and whatever rubber Lionel used- something either in the packing, oil, smoke fluid interacts with that rubber and turns it into just a gummy mess. Again something interacted and th engine never even ran one inch on the track.
So no, I highly doubt it is your track -especially with the rubber degradation symptom of drying out and cracking off- VS being stretched and just then roll off the wheels under stress. That is simply the rubber degrading because of it's chemical makeup and the environment (sunlight, oxygen, ozone, and any other chemical or fume exposure).
Again my advice is change the brand of rubber tire and find something else that fits your rim. Just saying, change the one variable - tire rubber compound by changing the source of your replacement tire when it's hard or difficult to change all the other parameters (environment).