How old is too old for a PC case?

I bought this Antec server tower for my first PC build in the early 2000s thinking that it was big enough to accommodate any future rebuilds and I'm still using it 20 years later. I had to be careful for my last rebuild a couple years ago due to the ridiculous size of GPUs but I've since removed one of the two 3.5" drive cages to make more room in the lower part of the case. I've never had any cooling problems and even with 6 80mm fans it's pretty quiet.