Exactly this. The gaming world is in need of a decent zoo simulator game right now. ZT2 came out 15 years ago! I cant even believe that, feels just like yesterday.I am going to stop you right there, I would like to shed some light with my experience to help bridge understanding as to why Planet Zoo should be its own game. I know that Frontier Developments know what they are doing as they separate Planet Zoo from Planet Coaster. I am sure you are familiar but for the rest of the forum folks here, I would like to explain why this is the case.
Planet Zoo has a lot riding behind it because this game has the most potential into tapping into the previous Zoo Tycoon series. Zoo Tycoon 1 and 2 garnered a very large following, until Zoo Tycoon 2013/2016 when Microsoft "dumbed" down the game to make it very friendly for children. The "tycoon" aspect of that game was gone. Since then there have been no zoo simulator games since.
To this entire forum, I say that Planet Zoo deserves a standalone game because of the large following of Zoo Tycoon fans looking for a reincarnation of what could have been in a Zoo Tycoon 3 series.
Least us not forget that Frontier Developments also helped develop the original Zoo Tycoon 1 & 2 series (edit: and the 2013/2016 version). They know what they are doing, they know their market/fanbase, and know that people want a zoo game, not a coaster game with zoo/animal assets and management