There are two common reasons to "care" and one that actually has merit, I'd say.
You've been without work, so you're a risk. You know how it's said that you can get more attention and dates when you're married? Someone vetted you and determined you're a good partner, so the work is already done for any other prospective partner. Same with jobs. It's why a job wants to hire someone already in a job. You're the safer bet that's already vetted by someone in that timeframe. We need Rockstar Ninjas, not people who are worldly from travelling.
You've got something to hide. Did you rage quit a job and end up in retail for a while? Sounds like a risk you'll rage quit here too. Maybe you had an asshole manager and it was a one off, but they don't know that. They only see the risk. Or if you were out of work due to a lay off, the gap shows nothing of what you were doing in that time and how that can help the company. We need Rockstar Ninjas, not flight risks.
You are out of date. In tech, this one kind of makes sense. Sure you may have been a JS dev 5 years ago, but do you know Angular 7? Vue? If the stack is on the bleeding edge, it's risky to hire someone with only old experience. We need Rockstar Ninjas, not old guys using Java 6 for everything.
As for what to do about that, always include a cover letter. Explain, as a human, what the story is behind your timeline. How there was a medical thing that has since resolved and you're excited to get the chance to work at Company due to x, y, z. Don't dwell on it -- just matter of factly a thing happened or yeah, I quit without anything lined up and I learned x in that meantime and am looking for an environment now with less of y.
There are two common reasons to "care" and one that actually has merit, I'd say.
As for what to do about that, always include a cover letter. Explain, as a human, what the story is behind your timeline. How there was a medical thing that has since resolved and you're excited to get the chance to work at Company due to x, y, z. Don't dwell on it -- just matter of factly a thing happened or yeah, I quit without anything lined up and I learned x in that meantime and am looking for an environment now with less of y.
Thanks for making the time and writing such a thoughtful and thorough reply. Highly appreciate it.