I personally think 8gb is the minimum you would want to have if you wish to run 1440p... Looking at watch dog legion benchmarks it looks like the game allocates around 8gb-9gb for 1440p at everything at ultra and ray tracing enabled.
Comparing this to a 2013 cross gen title, tomb raider 2013, which allocated 4gb at 1440p, with this new gen the vram requirements have kind of doubled.I know you can't just compare a different game to another game but its just an example here. I know some well optimised games will allocate only 6gb-8gb...But going forward it feels like almost all the new AAA titles will allocate around 8gb at 1440p at ultra settings.
Then 3 years later doom 2016 which was a true next gen title allocated around 5gb at ultra settings.
So looks like 8gb won't be *not enough* for 1080p/1440p for quite some time as long as you are okay with dropping texture pool down by a notch in a select few games that challenge the vram buffer. So I don't see any issues arising at 1440p for atleast 3 years, that is 2 years of cross gen and 1 year of true next gen games, after that I have no idea, maybe some optimised games will still let you use ultra but you will want to use high/medium because you will be getting way too less fps at ultra after 3 years due to your gpu horsepower being weak for those games to run at ultra.
They definitely gimped on the vram, but atleast its the minimum you need...
honestly, the 3070ti and 3080ti with 10gb and 12gb respectively, should have been the vram we should have gotten on the vanilla cards...
I wish amd comes up with a dlss alternative(major selling point for me) because I believe more is always better than less, while 16gb of vram is obviously overkill, i would like to have something like 12gb on my card to feel comfortable at 1440p... It is optimal for 4k.