Its called upselling.
I have never used any injector cleaner on any of my FI cars, and they are fine.

If the cabin filter is dirty I would change it..up to you what dirty is.

I hope they rotated your tires for you.

 

It's not a "low oil" indicator. It's just the maintenance minder which isn't aware of your oil level.

 

So for injector cleaning, I use Techron every now and then. Effectively, that's what the dealer would be doing, too.

So, injectors DO get dirty after many years, and a solution in a bottle isn't going to clean them. At that time, the only real solution is to remove them and ship them off for cleaning and flow testing. I did that before I went FI, and it was good that I did as one of them was more dribbling than spraying.