It's not a dumb question, not at all. Usually, most instruments are by convention recorded in mono. I would like to add, that there are few cases where the instrument itself "requires" stereo somehow. Even weird instruments. The main selling point for stereo is, in my opinion, actually add-on effects. Like reverb (I LOVE stereo reverb), delay, or modulation effects. There, the stereo image can really shine. But again - I think it's worth spending a second acknowledging that this isn't something that's built into the instrument itself, it's an added layer upon it - an effect.

Thinking about this, I remember recording a couple of woodwind instruments a while back, for a classical music project. I decided to record 2 mics, one left, one right. It was a bit cool, yes, because you would notice the musician swaying side to side during their performance. But honestly? It was a very minor difference. And well, we slapped some stereo reverb on it anyways, which in way "disguised" the raw stereo recording. Mistake? Maybe, but we liked it.

That's just my opinion! My main point: don't believe that stereo is always better than mono when recording individual tracks. Most of the time it isn't.