You can use nexus mods on all game versions, including the steam one.
For a mod to get uploaded to here, though, the modder has to own the game on steam. Not all of them want to buy the game again.

Many of the mods on Nexus have never been posted here,for many modded games.

There's still a ton of mods that need updated there, too to work with the new dlc. It's up to the modder to post their mods on Steam and elsewhere. Nexus needs to get mw5 mod support working again on Vortex.

One reason that comes to mind, is I think you have to own the Steam version of MW5 to post mods on the Steam Workshop. Where as with Nexusmods, you can have any version of MW5. I imagine not all modders feel like buying the game a second time, when they already got the EGS version previously.

Um,to directly answer the question at hand: Nexus,as a website/organization,has broader
artistic tolerances for the content there. I.e.: a mod might have some adult content. So Nexus
is a (more or less) thriving goto hub of game improving(mostly) artistry in the format of mods.
_Alot_ of different games and their mods hosted there. Go look. Steam has it's perks tho.
Just not all the mods. :)

As long as you are only using mods that have been UPDATED since May 26 2021, you can use the Nexus mods on the steam version of the game. I even prefer it as that way I don't have to be logged in (e.g. if my internet gets interrupted) to use the mods. However, using them through Steam ensures you have to be logged in.

I wonder if the Nexus mod makers could find someone (with this game on steam) to post their mods in the Workshop for them.
Obviously, the makers should be given credit.

Several of the mods I really wanted, on Nexus, wouldn't work with my (Steam) version. Although, I think most of them haven't been updated since before that 5-26-2021 date, so that's probably the issue. (I really wanted the mech size re-scale, and the time revision ones...)

"I wonder if the Nexus mod makers could find someone (with this game on steam) to post their mods in the Workshop for them."
You need the editor and the source files of the mod to be able to upload to Steam.

I figured that was the case, and that the original mod creator would supply all of that to their chosen intermediary.
However, if the only reason why some Nexus (non-steam) mods don't work, is because they haven't been updated, then it wouldn't help to have someone else upload it to steam, and I'm fine with downloading them from Nexus. (Automatic updates are nice though.)
Also, I can understand a mod creator not wanting to turn over the "essence" of their work to someone else.

Can someone teach me how to install mods not from steam on a steam version of the game?
I want to get Piratetech working on Steam but don't know how

Originally posted by paladin_du_cha0s:

Can someone teach me how to install mods not from steam on a steam version of the game?
I want to get Piratetech working on Steam but don't know how

Same way you'd install a mod on a non Steam version.
Extract to Steam\steamapps\common\MechWarrior 5 Mercenaries\MW5Mercs\Mods