I do yes. I swear at some point there was markdown or some variant that allowed one single-character thing for italics and another for bold (maybe * for bold and / for italic? And _ for underline?). These days I've mostly just given up using bold.

You are right, there was a convention using that as well: I still have it in my muscle memory too (I always expect bold with a single asterisk). But I can't remember when and what that was.

I still wouldn't go as far to say the MD or RST syntax is hard in any way (and really, asterisk which requires a Shift key is worse than double backticks).