AMD's tech is yet to be seen and the launch will be basically a dynamic down-res (AKA: garbage), so I wouldn't make any purchasing decisions until you see what they offer. I doubt AMD will come close to DLSS 2.0+ quality, at least for a while. And then you have no idea which games will even add support for it, while Nvidia already have quite a few titles under their belt.
Check the price and performance each card offers and also watch a few benchmarks to compare the 2 GPUs.
I'll post a link below from Hardware Unboxed so check it out when you have time.
As for DLSS 2.0, that's a judgment call you'll have to make down the line.