Yes we are very lucky on that department and just across the boarder in Germany even more zoos al very close.
Almost all zoos are also very modern with rare species.
Per example the zoo closest to my house is specialised in apes and monkeys and they had poboscis monkeys until recently (they where the only one in Europe), sadly two died short after each other so the last one was send to Singapore zoo I believe.
I see your point on the fish and I mostly agree, though I must say the fish are taken care of by keepers. In a Dutch program that followed staff in the zoo. they even did surgery on a koi I believe (although I can’t remember witch ).
If you count every structure with birds as an aviary there are two zoo without aviarys.
The one has no birds exept rheas and the other has pelicans, stork and flamingos, of coarse they are clipped but these birds are in most Dutch zoos.
So in average, aquariums and birds are not equally important I guess.
As a last add its fair to say, one zoo is an all bird zoo (they have some monkeys). Called avifauna.
On the other site burgers zoo Arnhem has the biggest aquarium in Europe I believe (at least the most impressive one

).