I have 2000+ hours in KSP and 70 hours in KSP2 (we don’t talk about that fail here). KSP has more content. Don‘t forget KSA is still pre-alpha. Where KSA excels is in its technological foundation. It‘s not just a game engine, it‘s a whole framework. Many of KSP’s limitations and clunkyness came from the use of the unity engine. KSA-devs are building a loadingscreen free, multithreading, true spiritual successor to KSP. Sadly with kittens instead of kerbals (but there are several mods that replace the kittens with kerbals, the devs love modding)