In Sweden there is a 6 month trial period unless you manage to negotiate that down in your contract. During that period you can be given 3 weeks notice at any time without reason. These rules only apply to people working full time.

If you have a time limited contract with a company and you keep getting work there multiple times, then over a 5 year period if you have worked at that company for a total of 12 months your contract is converted to a full time contract. This does not apply to part time jobs, however part time can also be converted to full time if your employer always schedules you for on average 40 hours then it is deemed that you have been employed as part time maliciously and your contract is converted to a time limited which in turn can instantly be converted to full time using the rules above. There are quite a few cashiers with full time employments because the manager was sloppy or didn't want to employ more people.

The most common way employers try to make people quit who are protected by law is by claiming they need to cut down due to economics, if the company is actually doing equally well compared to last year they can be legally forced to give you your job back or pay you damages equalling 6-12 months of salary, depending on what the court decides. This may also be literally impossible for the company since firings should be made based on the "last in first out rule" meaning you can't fire that lazy boomer without paying massive penalties.

Giving them really shit tasks or clients to make the bad employee quit is another classic, which can be effective. Usually the employee has a mental breakdown and goes on sick leave for 2-6 months (paid by the state) and never comes back.