Providing you're happy with 60fps and tweeking a few settings on some games then a Vega 56 should absolutely be able to power a 3440v1440 screen.
If you don't want to spend that much google electriq 3400 ultrawide - you can pick them up for between £290-£350. Both 1440p 34 inch ultrawides. I have the cheaper screen, as it's the older model and it's probably my favourite ever upgrade or at least up there. You can look up youtube reviews with it's original American name - Mass Drop Vast Ultrawide. Electriq rebadge other companies tech. I can't speak for the more expensive model but it's got a higher refresh 144hz v 100hz and I think it's curved.
Obviously games like Cyberpunk are GPU slayers though
Thanks for your reply pal.
I ended up getting the Dell 2721DGFA so a normal 27" IPS flat panel.
I figured that due to hardware being hard to get hold of and not much advancement over the last 12 months, I would hold off a full new build until 2022/23
This way, the monitor is more absorbing and doesn't push my system as much as the widescreen.
Hopefully when I do my final build, OLED style monitors will be far superior. I'm happy with this filler to last me for another few years. I just need to decide if to get a calabirator now to get the accurate colours.