If you find Starfield's NPC walking speed as infuriating as I do, try these mods

pcgamer.com:

Starfield is the latest in a long line of games to commit the cardinal but common sin of not making NPCs match the walking speed of the player. It sounds like a minor quibble, but it crops up so often that it's driving me loopy, resulting in me trotting ahead of NPCs while screaming at them as I completely lose the plot. 

Every single person in the galaxy seems to have had a meeting where they decided to walk just fast enough so that they outpace me when I'm walking, but slow enough so that I end up ahead of them when I'm jogging. Regardless of whether I'm using a mouse and keyboard or a controller, there is no way to match their pace. 

Since a lot of quests require you to follow an NPC, you'll find yourself stopping and starting constantly as you try to get to your destination. Some (but not all) NPCs will pick up the pace a bit if you run far enough ahead of them, but you'll still have to wait for them to catch up and, crucially, you won't actually have a quest marker showing you where they are taking you. 

It's kinda wild that this issue is still cropping up in 2023. It's present in Bethesda's previous games, and the studio is far from the only perpetrator of this heinous crime. And there's seemingly no logic behind it. There's an argument that it allows players who get distracted to easily catch up with an NPC, but there are already better solutions to this problem, like NPCs waiting if the player falls too far behind, or quest markers that show players where to find the NPC if they lose sight of them. Indeed, Starfield already employs the latter, making the NPC walking speed even more ridiculous.

Like so many of the recurring issues with Bethesda games, it's been left up to modders to fix this, which they've done