True, but as one's zoo grows, one needs more guests to provide money for the requisite staff and food for the animals etc. I've run into this issue when my largest couple of zoos got too bogged down to play comfortably. I tried restricting the number of guests, and it helped with performance, but then the zoo started to bleed money. Guests are the only source of income in the game at this time, so bigger zoos with more animals, staff, and attractions need more guests.Because of Covid everywhere in the world we have lockdowns. Lets reduce the number of possible guests in our zoos. That is possible in the planet Zoo options and helps to keep the FPS high.
I would absolutely love something like this in the GameI suppose the introduction of some alternative ways to obtain funding from grants, charitable contributions, or government agencies could change this dynamic and allow larger zoos to be less than 100% dependent on huge guest numbers. But if this route were available I'd suggest requiring something in return, such as a certain amount of research being done on animals (even after all species in the zoo are "maxed out") and a certain amount of breeding and release of endangered species.