Things like Spotify or your phone/earbuds themselves usually have a mono setting. I use it all the time when only wearing one earbud. Beatles songs are notorious for splitting vocals to one ear only.

The solution is already right there. But let me guess, “No, I want to use my old wired earbuds from 1995 and they should accommodate me in my archaic niche use case instead of me upgrading my earbuds to enjoy the new features developed like forced mono”?