There are no problems with this.
Indiana Jones takes a little more than 12GB of Vram in UHD settings and with all options.
As a rule, if you switch on all RT options, you will use DLSS in any case, so your statement is not correct / is at most an option in theory.

In general: 16GB Vram is more than sufficient for UHD gaming. Yes, even for the next few years.

Yes, there is still the 5090 with 32 for a slight surcharge of 1600Fr. You get a slight boost with the AI and a misconfigured fourth fan