"Not the greatest idea"
This past February, I gave Jira a spin as a personal task management system, using its free tier. I used it for a hot minute before ditching after Atlassian sent me the "Upgrade Now" email of doom, which I read one weekday morning, panicked, and exfil'd my data in early April, abandoning the platform. The root cause of this appears to have been the Premium free trial, which I didn't ask for, want, or need. This experience rather dominates my memory of the platform, but let's try to review it anyway.
Uhhh...
It was ok? Having the kanban board is fun, and I had set up an epic for my Wisconsin exfiltration scheme (hire me please).
However, it's awkward for a single user; I had to set up automation to assign myself to new issues. Reliability on mobile isn't the greatest, and as a result I got a bit neurotic about making sure that tasks were fully created before deleting them from my Google Keep cache.
Do I recommend? Not really. Jira isn't designed for single-user task management, and that's okay! The Kit Method does result in failures, and I'm not going to demand that a gaggle of Australians accommodate someone who's holding it wrong on purpose.
Now, one might wonder what I use now, and the answer is "a combination of Google Keep pinned notes, Google Tasks, and Google Calendar holds" (can you tell I use Android?)