Inactivity and not working is not the same. You can be pretty busy with personal or charitable projects whilst not working. So skills-wise it is not a problem

Inactivity and not working is not the same. You can be pretty busy with personal or charitable projects whilst not working. So skills-wise it is not a problem if you keep tinkering and learning new stuff, although not if you just take a 6 month holiday. You might have a harder time explaining the gap in your CV/Resume, especially to more blinkered enterprise companies but that is another issue.