Linux is already integral to the tech and enterprise worlds, which have a lot more money to throw around the consumer desktop space. I'm having trouble seeing how Linux becoming a more popular consumer OS would lead to the types of problems you're talking about, if being a leader in the server space hasn't already led to them.

Also, Linux has a built-in mechanism against enshittification, which is its open source and multiple flavors. Ubuntu becomes enshittified? Move to Fedora. You can have a dumbed down consumer-friendly distro without affecting Arch.