Development must occur in an isolated VM, with no access to the publishing workflow. CI operations must happen in a separate VM or on the host system after scanning all files. Thus, even if the development tools are compromised (like this case), the impact is limited.
Still, it’s hardly a surprise that best practices are rarely followed with any consistency.
Maybe because the tools aren't of much help. This is all theory but when you want to do it it's custom solutions and duct tape.
There is too much friction when you try to isolate things. You have to do custom stuff then the company won't let you virtualize (can't install stuff...) or won't allow you to enroll the vm and will threaten you if you dev on an OS that is not enrolled.
Best you can get from state-of-the-art-frontier-top-it-company is an IDE with an exec sandbox leaking like an hourglass.