The furthest I'll go is filling in 2-3 form fields or write a short cover "letter" in a form if I'm particularly interested and the job ad provided sufficient detail that I know there are particular parts of my experience worth calling out to them and explain how it relates to the job in ways that might not be obvious to the first line recruiter.

But yeah, if there isn't an "easy apply" button on a LinkedIn job ad it takes a lot before I'll click through and even more before I'll consider filling in yet another form.