It’s not “here to stay” it’s a feature that is used or not used depending on the level of realness wanted. Some are fine with hand waving away encumbrance, some are not.
If you’re playing a walking simulator, it is kinda part of the immersion.
If you’re running around killing every Greek god under the Sun, but suddenly you pick up your 7th weapon that’s just chains with something at the end of it, and BOOM you can’t move anymore cuz your too heavy, then it’s getting in the way. Instead of implementing encumbrance they just, limit you to 6 weapons and tada, they could explain it as “it’s too much weight” but they won’t give you the option for it to happen as slowing you down would kill the pace and feel of the game.
Baldurs gate is a DND based CRPG and Starfield is a loadscreenwalking simulator. Of course they have encumbrance.