because macOS comes with sideloading baked into it, which would kill the massive massive monopoly App Store revenue rort. Never gonna happen without govt intervention.Wow. Calculator alone grant a new iPad Pro for over $1000. /s
Seriously, why not just put MacOS on iPad rather kneecapping iPad with iPadOS?
Same reason why macOS is never getting a touch screen... because that would cut into iPad sales, which would cut into said App Store revenue.