I can sort of almost see the point, as a presentation aid, or for still photography. I’ve gotten a little bit back “into” photography in recent years, having previously been into it as a kid, but now swapped blackout curtains and chemicals for software.
I view my processed photos a lot on the TV, so I initially started to crop everything to a perfect 16:9 aspect ratio. I soon kicked that habit, because many photos have a “natural” shape that is nothing like 16:9. Sometimes it might be portrait, sometimes landscape, and sometimes fairly square. So when seen on my TV these days, most are either pillar boxed or letter boxed, to a greater or lesser extent. After all, if you visit an art gallery, the best pictures are not all the same aspect ratio?
What I do detest, and makes my blood boil, is when BBC want to show some footage taken on a phone in portrait. Instead of just pillar-boxing it, they generate some truly horrible synthetic effects to fill the black areas. I can’t over emphasise how much I that, when simple pillar boxing would be fine.