RTX cards in general have better DX12 performance than the 10 series. (Forza horizon 4 seems to be one of the few outliers) So they're of course a little more future proof than a 1080ti.(even though higher vram)
Ray tracing in general seems to be a good thing for slower paced games like tomb raider, but in fast paced shooters I'm not appreciating the shadows as I'm busy trying to find enemies vs looking at the scenery.
Tend to agree on the sell both and get the new king of the hill RTX 2080Ti but as stated before the price is ridiculous. We need to vote with our wallets and show them were not playing that game.