Tests and version control still have immense value when working solo.
Tests help with ensuring that you don't introduce regressions, and that you can safely refactor. It's likely that you test changes manually anyway, so having automated tests simply formalizes this, and saves you time and effort in the long run.
Version control helps you see why a change was done, and the ability to revert changes, over longer periods of time. We tend to forget this even after a few weeks, so having a clean version control history is also helpful for the future version of you.
Not having the discipline to maintain both, and choosing to ignore them completely, is just insane to me. But, hey, whatever works for OP. I just wouldn't expect anyone else to want to work with them.
The only scenario where I could conceive not using either is in very small projects with a short lifespan: throwaway scripts, and the like. The author is writing their own language and virtual machine, which don't really align with this. Knowing their philosophy, I would hesitate to use anything they made, let alone contribute to it.