Me upgrading from the 4090 will depend on a few things
1- ( most importantly ) is there a software exclusive tied to the 5000 series? Usually, they stick with new features for 2 generations. DLSS came with 2000, and stayed with 3000, but the 4000 series got Frame generation, in general, the 5000 shouldn't have something that is not available for 4000 users. especially when there is no need for Nvidia to release it exclusively since AMD is out of high-end market.
2- how much more powerful is the 5090 to 4090, it looks like around 70 to 80% more powerful. That's a good number to upgrade to. also, what is the performance difference between 4090 and 5080? IMO i think the 4090 will hold its value and will be more in demand than the 5080 if the performance is only 10% as this doesn't count for shit. but 16 gigs to 24 gigs is more important IMO.
3- The price. 32gig GDDR7 for the 5090 I am going to assume this is at least around 2000$ US. That is $ 2700$ CAD plus tax, now we are talking about 3000+ for me for the FE if i am lucky to get one of these.
I wouldn't pay this much for a video card even if the future my gaming is on the line. just to be outclassed by a TI or a super 1 or 2 years after.