Comment by Sodman

You definitely don't need a personal website, blog, or even github for most jobs. If you're cold-applying to jobs online, and you don't have a linkedIn it will be seen as a red flag by some hiring managers - easier to lie/exaggerate about employment history, durations, title inflation, etc. Also more likely that you might be trying to work multiple jobs at once. LinkedIn doesn't need to be fully fleshed out with a ton of content or even any activity, but just a public list of companies you've worked at, rough timelines and titles, is enough to reassure most hiring managers.