When you have lower spec hardware to develop for, things will sometimes take a hit. A lot of devs complained about Series S and Microsoft's parity requirement. Assets and general game design will sometimes take a hit, it's not as simple as dropping the resolution and lowering the framerate for lower spec. If a dev goes into developing a game with a baseline of a certain spec they will usually code for it and higher. Imagine if TLOU 2 had to run on much weaker machines or multiple specs and Sony couldn't optimize to the metal. TLOU 2 was literally downgraded and we never got the E3 2018 version. If what you are saying is true then why are games, even games that could run at maximum potential on powerful PCs downgraded before launch?
Can't really trust trailers, plenty aren't even real, like the Anthem one. Software dev is variable/adaptive and many aspects can change. For the real gameplay ones that run the actual game and arent cgi, i believe they configure everything past the point of efficiency to show off in the best light and then ship with restrictions where they find a good balance for general performance.
To this point,
max settings arent the max settings, just the highest options the devs choose to allow for the user, in this sense every game is downgraded for public.
Which is why i pretty much just look at what ships and not trailers, in many cases the games look better once I have them in hand than the trailers, but that's most likely because of video compression destroying details and improvements or additions done during development (even post launch), the latter 2 imo being clear indicators that the trailers were indeed real.
What did Larian and Wukong devs do about Series S? They didnt bother with it for launch and skipped it, there werent any downgrades to other builds in order to accomodate for it, this was pretty much done with a final product, if accomodated for early enough or from the start it only gets easier. Memory/CPU could hard limit devs, but i dont see anything ambitious happening on those fronts, even Flight Sim which is imo the most ambitious game is scaled down to XSS, if the devices will have enough CPU horsepower and enough memory, i would worry, engines are more scalable than ever.
I could only theorize on what non-unreal engine devs used to (and still) do when they show-off gameplay with all the stuff seemingly working years before launch, i just dont know and each case is likely a different answer. No idea what TLOU2 looked on last gen, so ill take your word for it, ive only played the remaster on PC and remember that i wasnt happy with the visuals either. Consoles are a foreign world to me, i have zero worries about multiplatform/UE5 games and those are the cutting edge ones.
Now i am curious to find out how TLOU2 looks on the lowest settings, i am gonna have some fun once i get some free time.