The 'vanilla' experience.

[Aarkreinsil]

I'm actually kinda paranoid about trying out and adding new mods, since they might stop being updated just when I end up being totally addicted to them (that just happened way too often).

Then again I saw a lot of my "must have" mods being integrated into the main game. Apparello comes to mind, it originally just allowed you to craft clothing, armor, then even weapons. Now we got that in vanilla.

EPoE is another mod that I really need in order to play for my "vanilla" experience in that regard. The prosthesis crafting in it has gotten pretty expensive now that they also incorporate components, the research blends in nicely with all the other stuff and I think it's just a matter of time until at least some of it's features will arrive in vanilla. Sometimes I can't even tell it's not part of the base game.
Even mods like Fuse Box or the central heating and heat distribution mod still feel like additions that could have very well been made to vanilla.

I think for me it's just that I don't want to rely on RNG too much. Being able to research and craft the things that vanilla already has to offer is a big part of the game for me. If all of that was gone, I'd mostly just sit there and wait for a trader or an enemy to bring a certain thing, and that just feels like a grind.

Now one could argue that even pretty light mods like "Prepare Carefully" take out some of the intended Rimworld 'FUN', but who wouldn't land on an ice sheet naked or with just a t-shirt? No biggie. 

Still, I think the 'vanilla' line is drawn with mods that change the base game experience enough so you really have to start a new map, or when they add a ton of new and possibly overpowered items. Total overhauls, huge industrial/tech mods or gameplay changes like Combat Realism fit into this category, as I would definitely start a new colony just to try them out.