This. Everybody I know uses LinkedIn as their de-facto resume. It is their most up to date and complete CV with all roles, dates, recommendations, education information, skills, links to projects etc.
LinkedIn actually rolled out a new feature "Easy Apply" or something where all you need to do is click an Apply button and it (presumably) sends your profile information to the job.
Most resume's in non-technical fields (think management, banking, consulting, law etc) will have line items of deals/projects/responsibilities with rich information of how many people they've managed, the size of the deal, type of work etc.
Most of the time people don't want to post this on LinkedIn as its too public of a space to go about bragging of your achievements at employer X. With this system, Google basically has a window into this more specific information.
It's possible to load up a traditional resume with 5-10 pages of granular detail like this, but that's actually more awkward than helpful. Once a (shorter) resume establishes basic competence, employers generally want to do the next round of screening based on face-to-face contact. Asking the resume to do all the work will lead you to hire the very best resume writers, rather than the very best candidates. (Note that strong passive candidates, who already have good jobs, do not spend a lot of time polishing their resumes.)
In non-technical fields, taking candidates through a face-to-face interview tends to be the best way of gauging grit, creativity, motivation, fit/compatibility, etc. That's especially true if the job specs are still fluid. In that case, a face-to-face interview lets both sides play around with the job description a bit.
Google is supremely good at coming up with engineering solution to engineering problems, and its decision to build an applicant tracking system is encouraging. But Google also is a bit prone to taking the same approach, no matter what. If we're talking about the full sweep of candidate assessment, that isn't an engineering problem.
We (Triplebyte) don't ask engineers where they've worked until the end of the final interview. It's the last thing we ask (after all the technical evaluation and scoring is done). We regularly find and pass great programmers who are totally self-taught (and would have been screened out by any resume screen process). We ask about previous work at the end because we want statistics on who is applying to us. This lets us compare our process to more traditional credential screens (I write about this on our blog)
I'm willing to believe that my memory is wrong and the question came later. But "resumes when we ask for them, which we guarantee we will do" is not quite the same policy as "no resumes".
LinkedIn definitely has very rich resume data.