Why are the developers against modding the game?

On Steam, Discord, and some posts here, I read that the devs are strictly against mods. You can't even talk about it on the discord server.

What I want to know is why? I really hope my post doesn't get deleted, as I'm not distributing or requesting a mod. I just want to understand why the devs have such a negative stance towards it.

Games like Lethal Company have countless of mods available that don't ruin the experience for anyone. Why can't we have the same thing with Phasmophobia as well? I understand that devs are busy on game updates and making the game available for consoles, so why not let other people add content to their game for literally free?

I'm not talking about cheating, but about more skins, funny sounds (like the yippeee), weird hats and accessories to add to your player, put a funny hat on a ghost, some mini games to pass time while being dead/ghost, a mimic that mimics the voice of players, weird but funny jumpscares - like opening a wardrobe and a cat meows/jumps at you (then you can keep it in the van).

Things like that. I'm not talking about "competition" with the devs, as in making new maps that potentially turn out to be better than the current maps and the devs get jealous (a person on Steam mentioned that some devs have a big ego, I know nothing about it, it's just someone else's opinion on why they don't allow mods), I'm talking about relatively cosmetic changes.

What's y'all's opinion on mods? And if I ever get lucky enough to be noticed - why do you, devs, hate mods so much?