You buy the Mayors' pass to get the buildings that are in there. You also get currency, which you can use to buy some more buildings.
As much as I, too, dislike being shown a lot of stuff that I won't be able to get, the current Mayors' Pass isn't a bad deal or anything. Some of the criticism surrounding the new way seasons are done is valid (like a lack of transparency regarding how much currency we can actually earn), some is not. Fact is, the current pass certainly isn't a bad deal in terms of how many buildings you can get, if you compare it with earlier seasons. It's probably even better now, depending on how much extra currency you collect.
Before, you bought a pass and you got 6 buildings. Which ones? That was entirely determined by EA. Now, however, you get four from the pass and currency which you can use to buy at least 2 more. It's easily the same number of buildings, even more if you pick the cheaper ones (like Gardencourt Estate, which in my opinion is among the best buildings available). The added advantage here is that you get a lot more choice, getting the option to pick the ones you like and ignore the rest. Let's be honest: in previous seasons there were always some (though, between players, differing) buildings included in the MP that many of us didn't care about, but they were included in the deal. Now part of the deal is that we get currency and can just supplement the pass with stuff we actually want.
Maybe people are just looking at this the wrong way. You don't get less than before. You can get as many buildings per season as before, the only difference is that you get presented with even more buildings. Can we get all of those? No, but perhaps getting disappointed over this is more a matter of setting reasonable expectations. Fact is, in terms of buildings, you certainly won't get less out of it than before and we have more choice now. I think €9 for four buildings and currency to buy at least 2 more, with more choice and more agency than before, isn't such a bad deal.
There are plenty of reasons to complain, but to suggest the MP has lost its value seems to be a misconception. Don't focus on what you can't get, ask yourself the question how much you get now vs. earlier seasons. I think you'll find that things have improved, in that sense.