Look, you started by saying Bethesda games don't have encumbrance but Skyrim was the first game I thought of that had stuff you couldn't use but had some kind of value and weight and encumbrance was a huge part of Skyrim when wearing heavy armor. There is even a whole strategy of figuring out value for the weight to increase the amount of value you get when selling. Baldur's Gate 3 and I assume earlier ones have the same thing.

We are talking about the games that have those things when saying they are an issue. Of course it isn't an issue in games that don't have it, but when it exists it absolutely is an issue, especially when game mechanics include a 'loot all' option. There you need to drop what you don't want.

Hell, inventory management by space and encumbrance have been a thing for all the years I have played rpgs. Not having either seems more like the exception to me.

Morrowind you can craft potions with ridiculous value, then use that to pay for levels from trainers and buy the best items

Did you actually play Morrowind? I can't think of a single one of the best items in Morrowind that was available for sale. You either had to steal them or they were loot. Also most of the vendors in that game were pretty broke. To sell anything of "ridiculous value" You had to find the mudcrab merchant out in the middle of nowhere. Gold didn't trivialize that game at all. Exploiting alchemy did.