I don't know that a 3-month temporary offer is really necessary. In California at least, where employment is "at-will", you can fire an employee at any time for almost any reason. My expectation when accepting a job offer is that if I am not successful in my role, I will be fired. Most jobs I have worked even have an official "probation period" for new employees where you have a set of goals you need to accomplish in your first 3 months of work, followed by formal review process with your manager and HR.
It's rare to fire new employees in their first few months, but it does happen. Similarly I have seen people join a company, and leave after their first week because a better job offer came in. It sucks when it happens... but overall I'd say the system works pretty well.
> I don't know that a 3-month temporary offer is really necessary. In California at least, where employment is "at-will",
Yeah, in an at-will state you might as well consider the "trial" period to be in place no matter what. If things don't work out well they'll just toss your ass to the curb. Maybe if you're lucky like me your boss will have a soul and give you some amount of severance at least.
When I took my first job I just assumed that it was a sort of trial.
Two people were hired. Me and another dude.
The other dude was invited to look elsewhere (they let him stay and work while he looked for a job so that was very nice), and I got a series of raises after they clearly were comfortable with me. They then started looking for a replacement for the other dude.
Effectively I assumed (correctly) I was on a sort of "trial" anyway.
It's rare to fire new employees in their first few months, but it does happen. Similarly I have seen people join a company, and leave after their first week because a better job offer came in. It sucks when it happens... but overall I'd say the system works pretty well.