I think this is mostly a US thing. Why use yearly salary? You’re not paid once a year, are you? Most likely once a month. Referencing monthly salary makes much more sense.
“I’m making 50k”. Great, now I have to guess - dollars? Monthly? Yearly? If yearly then what’s the monthly paycheck? Net? Gross?
For the US, but going by this thread it’s not limited to here.
Also, for what it’s worth, I would think if op was in a place that used monthly as the standard they wouldn’t have posted this complaint. If that’s not the case I’m confused by the point of this post?