Ms has in fact become very popular to use by anyone under 40 (I even know some older women who use it).
I am in my early 30’s, never been married, and I use Ms. because I view the use of miss and mrs. as a way to differentiate between married and unmarried woman idiotic and anti women freedom. Socially it was a way of chaining women to a specific social construct based solely on whether she is married or not.
I mean, men don’t change their title once they get married, they remain Mr.
Hence “Ms.” being used more and more by (mostly younger generations - i’d say x gen and above) married and unmarried women.
I always correct anyone who calls me miss, depending on my mood I may add a bit of a lesson about the wrongness or using miss or mrs when addressing women in today modern society.