Mandatory military service only trains them in the basics so they are ready when the risk becomes reality.
Switzerland has mandatory service. France used to have mandatory service. It never created what your said it creates.
I think you’re making a lot of assumptions.
In Switzerland, the basic training lasts a year I think? And is meant to teach how the army works and how to use weapons and not just rifles and pistols and knives. Depending on their role they also learn how to use artillery, mortars, how to use maps, how to use vehicles and tanks, how to make calculations and navigate and so much more.
The whole point of this is that when shit hits the fan, any additional training takes a lot less time.
It has to be well implemented and taught well. Maybe in your case it wasn’t and you have a bad experience of it.
Any country that’s serious about training it’s people to be ready for combat in case of a serious invasion will probably do a better job than one that isn’t because they want to be prepared.
In any case, I can understand why you would feel the way you do if it was implemented poorly in your country.