I've been hiring for software developers for 10+ years, and I'll put it this way: It was never needed but it certainly helps.
I don't expect anyone to necessarily have a GitHub account and active portfolio worth looking at. I do expect every candidate to give me enough information in their resume to quickly and accurately vet them. And to realize that if I can't vet the candidate, the easiest thing to do is put the resume in the "no" column.
Anything you can do to give a potential employer more reasons to respect your skills, the better, so long as you don't inundate them with minutia. Github accounts help, active LinkedIn accounts with a reasonable number of connections helps, resumes with good details, a work history that makes sense, good GPAs, and a clear statement on work accomplished and applicable skills helps.
The more the better, as long as it's terse and I can read through it in 15 minutes or less.
And none of that really changes from 0 years to 30 years of experience. The only difference is that you have to support the experience and seniority you have, and the more you have, the stronger a case you must make. If you don't like sharing your projects, that's fine, but you need a good, solid, write up of the work you've done on the job, and it needs to speak to the experience you claim.