By buying, I mean rewarding, since mods are usually created voluntarily with dedication.
I don't know about you, but I tend to focus almlst entirely on the immersion, realism and controls of the game, rather than multiplayer which I never really liked to play with other people online. Up until now, I realized the reason I kept on playing the game (and I'm sure 99% of you also do) is how the mods are drastically improving the immersion, realism and control of the game, which the base game would be rather empty and dull without it.
With mods going into the base game, the devs would only have to sometimes expand from that mod to their preference, but also make some fixes so that the mod becomes more playable. Personally, I have so many immersion-improving mods at one point, I couldn't even know what was making the game, and now I have to accept whatever error there is, because I only wished the game would become much more immersive than the base game, from more diverse firearms, makeshift armory to throwing corpses out the window and even gun suicide. You should be glad you're backed by dedicated modders who made the game much more immersive to learn from, while focusing on much more important matters, such as human NPCs and hunting.
Now, as much as I like to have immersion-improving mods in the base game, this remains to be my opinion, which I admit would still need to be further discussed.