Applying is easy enough as it is. Developer jobs typically don't have complicated forms to fill, assuming you're a developer?

The challenge is not the time to apply, but the time to do the coding tests and phone tests and onsite interviews. Days for each company, which doesn't scale.

Consider that if you make applying more streamlined, you will actively hurt the chances to get a job. You want it to be one click, like linkedin? Guess what, companies are flooded by applications, hundreds -if not thousands- of applications from anyone and anything, it's just one click, so easy to apply. It's totally unmanageable to review so they're never read. Remember that there has to be human on the other side to review resumes and schedule phone calls.