Should people be able to leave armed forces whenever

I will be the first to say I’m not the most educated on the process of joining/leaving armed forces but I do respect those who are in anyway involved with it. If my wording isn’t correct please keep that in mind. Anyways I find it absurd that a person who joins the military is not allowed to simply leave when they no longer want to be apart of it. Whether it’s just after basic training and you realize you can’t handle it or your beliefs have changed or whatever the case may be. It’s crazy to me that you can be jailed for trying to leave if you wanted to. I think in general no one should be expected to stay in that position when they no longer want to be there, unless in a time where it’s a necessity and people are being drafted yadda yadda. But at the very minimum I think anyone who as given any amount of time to their country in that way (or attempted to) at the very least deserves to go as they please. Maybe this is actually the case and I’m just not as informed as I should be but I guess I’ll find out in the comments what you all think haha