Your question is a perfect example of identity politics.

Most political parties want mostly the same things. They have differences in priorities, and they may oppose the specific means other parties propose, but they are rarely opposed to the actual goals of the parties on the other side of the political spectrum.

Radical fringes often have too different visions of the society to work with those on the other side. But we are not talking about radicals here, but a coalition of three moderate center-left / center-right parties. Those parties should be able to collaborate most of the time, even if you add CDU (another center-right party) to the mix.

I imagine the argument here is: FDP wants lower energy prices enough to horse trade with Greens for new conservation designations. That kind of thing.

Well, they claimed for years they wanted to strengthen civil liberties, stop surveillance, progress digitalisation of government etc. That all should have worked well with their coalition partners and the fact that they never actually intended to do these things and thus didn't certainly plays a role in that they lost so much voter approval, even if the keep telling themselves the only reason is that the were not neoliberal enough!