Question about gameplay and mods

You are right. If your bf doesn't see the problem, it's a him problem, not yours. To put it simply, without updating your game:

1.  You cannot obtain the last bug fixes EA/Maxis released.
2.  You cannot repair your game in the EA app (because repairing the game automatically downloads the game update).
3.  You cannot buy new packs (newer packs need the lastest update).
4.  You cannot participate in the online Events.

So it's always best to update your mods. 

Mods are a double-edged sword in a lot of ways.  GiardiniDiMarzo has already covered why you need to keep your mods updated so no need to repeat what they've said.  But you can help yourself by being very selective about what mods you use; how many you use and if the mod creators continue to support their mods.  Fewer mods are better imo.  I've been using mods since my Sims 2 days and if you keep the number down, you have fewer problems and when we get a game update, there are fewer things that break.  For those that I use, I check the creators' online site (Patreon, Tumblr, Discord, etc.) at least once or twice a week to make sure I have the latest versions.  It only takes a couple of minutes when I do that, and I encourage you to do the same.  I also regularly look at online resources that track broken and updated mods.  luthienrising posts a running list of broken mods after every update and keeps it updated so you can find out if what you use has broken and when it gets updated.  You can find that here in the mods section.  There are also many Discord sites that have mod sections that will tell you much the same thing.  

Hope this helps.