To be fair, Bethesda is owned by Microsoft. Even before the acquisition, they had no interest in supporting Linux (and I think this is significantly too demanding for the Steam Deck).
Strange to see that 6800XT and 2080 are recommended when they aren't in the same ballpark of general performance at all, as far as tomshardware benchmarks and hierarchy chart is concerned. I suppose their recommended settings probably includes some ray tracing options, which is dragging down 6800XT.
This also means 3070ti will perform fine as it performs much better in ray tracing compared to either of those recommended cards. And disabling ray tracing will increase fps as well, so that will also remain an option if push comes to shove.