like what if linux still was open source but had a lot of proprietary dependencies and packages and became more popular and therefore proprietary software came to it?? but it still would let you use any desktop environment and there would be a new proprietary desktop environment which was like gnome but easier
Linux is a kernel which is often bundled with proprietary components. Android, for example uses the Linux kernel. The whole desktop operating system you seem to be thinking of is a Linux distribution.
There have been many Linux distributions with proprietary components over the years. SUSE’s YaST configuration tool used to be proprietary, for example. There’s probably something current along the same lines, but there’s not much demand for semi-proprietary desktop Linux.