To be fair, B1 and especially B2 are not trivial requirements. A1 you will "pick up" like you say, but it's easy to fall into a trap of remaining around A2 without sustained effortful studying. (If you try to do it through just interacting with natives with no structure it's common to fossilize mistakes which take much longer to fix, or even just become permanent)

Personally I've gotten to B2 (not Germany) which is enough for most purposes, but it would have been very possible to get stuck in a rut.

It's very common for couples that move here for one to have a job, and the other to spend some months unemployed looking for a job. It's generally observed that those that have the job learn the job much slower and get stuck, and the ones that spend time at home and looking have much better outcomes longer term