In my opinion, what you're seeing is either: 1. People are unaware of this difference and just throw terms around for better prestige 2. More people are actually upskilling/getting certified to a "software engineer" to stand out from the competition in today's competitive and demanding job market.
I used to ask myself the same question a year ago, but with regards to the rise of people calling themselves "influencers" or "life coaches" lol.