Hi Iwalter.I have a recently self built Gaming rig. Ryzen 5800X with a used RTX 2080ti. I'm not subsidizing scalpers. I had a 2080 Super and after selling it I moved up for $150.00. Depending on scenery I can run from 50 to 90 FPS at 4K. I have a 27 inch 4K Dell Ultrasharp that I used with my photography work. Stunning monitor, but does not have adaptive sync. So I bought a Dell S3220DGF 32 inch, 165 hz Free Sync VA panel monitor. I hated it Not sharp at the edges at all. Although the experts tell us that 110 pixels/inch is sufficient for the human eye, I disagree. Nothing was sharp on it. QHD on a 27 inch monitor is borderline and absolutely not enough resolution for a 32 inch monitor.
So I bought a 38 inch LG Ultra Gear LG 38GL950G IPS display with G-Sync. This had 3840 x 1600 resolution, but those 1600 lines where spread on a taller screen and still only produced 110 pixels/inch. This was a ridiculously expensive monitor and I tried to love it but I returned it. I don't fly air to air online combat and I may not for a while as I am new to DCS World and this is a big learning curve. I realized that at high settings I hover between 50 and 80 FPS and 60 FPS is just great for single player. So I bought an LG 32UN650-W 4K- 32" UltraFine IPS UHD Monitor with FreeSync. Free Sync works just fine with My RTX 2080Ti. I now have 135 pixels/inch. Clear crisp cockpit details and great color and detail everywhere. Yes I am stuck at 60 FPS, but I have true 4K, a big screen and I only paid $500.00 vs the $1700.00 that the 3840 x 1600 LG gaming monitor cost.
So if you are going 4K at high settings, at 60 FPS I think the 3070 falls short of the 2080Ti, which is necessary to run 4K at 60 FPS. So the 3070 will not make 60 FPS at 4K high settings and the 3080 is overkill for 4K 60 FPS, but gives you the option to upgrade to a faster 4K Free or G-Sync monitor although they are really pricy now. Optionally, the rumor is that DCS World is in the near future moving from DX11 to the Vukcan API and if that happens then framerates should go up considerably and then the 3070 will run 4K at 60 FPS, but there is no verified timeline that I have seen.
My take on DCS World or any flying sim, is that the quality and clarity of the display is the biggest part of the enjoyment. It is what immerses us and nothing does it like true 4K.
So these are my observations and I offer them as food for thought and in no way suggest that there aren't other points of view to consider. Hope you are lucky enough to get a new 30 series RTX at a good price.