In the case of rent control -- landlords and future renters suffer. In the case the employment -- it's employers and future workers.
i don't know how rentcontrol works elsewhere, but in germany generally it means that rent can't be raised more than once a year or 15 months or something in that range, and it can't be raised more than a few percent each time, but it doesn't mean that it can't be raised at all. not being able to evict a tenant is independent of that.
the general issue here is a power differential. big company vs small family. i know in the US there are more small landlords who only have a few houses or even one. but that is rare in germany. most are bigger businesses with hundreds of apartments, and with that the risk of getting a bad tenant is obviously larger, but the financial risk is also spread over all tenants.
Strong worker protection ends up making the cost of hiring new workers higher. Companies react to those costs by a number of means like delaying hiring, hiring contractors first, firing within the probation period when they might not have normally, etc, etc. Whenever the laws are changed, a new "optimum approach" is developed.
And like rent control, labor laws often benefit the people who already rent/have a job. For people who are looking to rent/looking for a job, they can make it harder as the barriers to entry just got higher.
It's not right or wrong, it's just a trade off.