I never need a mountain bike for my non-road riding, let alone when I used to commute on bike - I always used what was called a hybrid bike but never liked the limited hand positions of flat bars. So, I added bar ends.

When gravel bikes started to come out, to me they were hybrid bikes with drop bars - exactly what I wanted. So, I donated the 25 year old Schwinn hybrid to a biking charity and bought a Jamis "hybrid with drop bars" or what is now called a gravel bike, which also included 2020 era components vs 1990 era!

They can call them whatever they want - I buy types of bikes for what I need for the riding I do. I've been driving a Subaru station wagon for many years - apparently no one wants to buy station wagons so they are called crossover utility vehicles now... When I bought my first one back in 2003 or so, no one wanted to buy a green car, so the green version paint color was called "Forest Blue."