I'll tell you why people want a 15in laptop, if not larger. Because they want a larger screen. My work laptop is a 17in Dell from 2018 and weighs just over 6lbs. so that's two Airs. I carry it to work every day, a walk about 1.3 miles, so 2.6 in total. It's not heavy, not in a laptop backpack, with the weight distributed.
Why do I have a 17in laptop? Because in 2018 that was the largest laptop available.
Why do I want a large laptop? Because when I'm at client sites, I usually don't have the option to use a second monitor. They don't have one. Sure, I could bring a portable monitor with me, but they add weight. Plus it would have to be small enough (meaning 17" or smaller) to fit in a laptop bag. Anything larger, then I'm schlepping a piece of luggage.
I get some people want smaller, compact, easy to fit in a small shoulder bag or purse, but some of use want, or just flat out need, a larger laptop. I'll do my work on a 15, if I have to, but I don't like it. On a 14 or lower, there just isn't enough screen for what I need.
I have an original 13" Air (sadly recently deceased) and I used it for work very infrequently. It was extremely difficult to use. Everything was just to small, or just flat out didn't fit on the screen, so I was constantly scrolling viewports around.
I get it. Small screens works for you. Great. They don't for me. I'm not even saying the larger laptops are popular, but for the small group of people who need it, we need it.
All I'm asking, on behalf of those that have different needs than you, is please let us have the equipment we need, and not the equipment you need.