Why would I stop the players from having their characters loot things?
Of course we also play with a vague nod to encumbrance.... we don't track it - unless it starts getting ridiculous. Then we'll do the rules & math.
But until then? If it seems reasonable, go for it. Carry all the battered junk you like around.
Now at some point this will become a transport problem for you to solve.
And on my end? I have the best deterrent of them all. I'm the DM. All the $ in the game comes from me. I play the merchants your characters will deal with in order to sell the junk. And my merchants aren't buying. Doesn't matter that the book says x can be sold for 1/2 value etc., the books not the DM, I am. And I say that the merchant tells you "Sorry, there's no market for crappy goblin swords." & refuses to buy them.
But if you persist - and I've had players do that - I'll have the merchants give you the grand run around. "Hey! Maybe Franco over on Water street." Franco then sends you to his cousin Bob. Etc Etcetc And eventually you run afoul of the Arms & Armour merchants guild, get arrested for selling without membership & fined at about 65% of the value the junk would've cost if it weren't junk. Oh, and it gets confiscated.
So you can go on a grand futile quest to sell random junk, or you can go on a real adventure. Either ways OK with me - afterall, it's all adding to the story....
But I'm not going to stop you from carrying looted junk around if that's your thing.