To be fair, some are worse than others. I have Transformers from 30 years ago that are fine, but figures from 3-4 years ago with the plastic deteriorating. My first experience with "Matty rot" left me a bit shocked until I read more about it and how to clean it off.
So I was going to go with statues more, but then hear about paint cracking, flaking, bubbling, or the statues themselves chipping or cracking more with age.
Beyond "turning over" my collection and making sure to sell some stuff before it reaches a stage of deterioration, I'm just resigned to enjoying it while I have it. It's not like I can take it with me. To be honest, I hope my desire to collect gets more in check in the years to come. There's so much I can't display it all at one time anyway.
I did stop collecting for a few years almost cold turkey. I told myself experiences in life were worth more and put that money to gaining those experiences. I have some great memories but have found that isn't sustainable either. So I'm searching out the happy middle ground.