I agree it gets a bit repetitive, you can find good spots for buildings but besides wonders and unique quarters there's not much you can do to change what spots will be best for what. There's no real reason not to build the buildings even if you lack good adjacency spots for them imo, so it normally becomes a case of 'build whatever I've unlocked wherever gets me the highest adjacency', so it's hard to naturally specialise a city unless it has a lot of coast/mountains/resources.
I don't think giving regular buildings adjacencies to other buildings would be a solution though, that'd become a planning nightmare. But some sort of special constructible adjacency-booster or specialisation-like mechanic for cities perhaps?
They've talked before iirc about their design goals of complexity arising through interactions of simple systems - theyve simplified city planning really well and I like it conceptually, but introducing another basic system to go with it would allow for more depth and variety imo.