I think there’s a more common problematic issue with plane seats… for taller people… leg room.
My hubby is 5’11”tall and in planes, his knees are crammed up against front seat!
He’s onk 83 kgs and it’s not width required, it’s length.
The airline companies are trying to squeeze in more passenger seats by shortening leg room space!
And… if you want more leg room … you have to pay extra!
We once travelled business class to Singapore… there was a fantastic special of $800 each instead of $400 cattle class…. So I grabbed the chance to tick it off bucket list.
I loved the noise cancelling earphones…. Couldn’t hear the plane engine at all!
And as much Baileys on ice as I wanted

Apart from that … the cattle class seat space is atrocious!
The worst (and last time I travelled international) with China Eastern in 2019 (before corona) was the worst flight, our morning plane was late and cancelled us out to get next flight 8 pm and I was stuck in the middle aisle of 4 seats and my ankles just blew up! So late in the day then 14 hour flight… I had never had such swollen ankles and I was frightened… I got out of seat walking up and down aisles and then went and stood in kitchen at 2am….just mortified and tired wishing I could sleep but worried instead about this DVT…..then a airline hostess came to get some ice…lightbulb moment…. I had an idea… I asked if I could have ice in 2 plastic bags.
He agreed and I went back to seat, put ice on ankles, and swelling eased!
Now for anyone else my ankles may not have looked swollen because I have very skinny ankles… but it felt like they were ballooned and about to burst.
As for arm rests… it’s only one shared between 2 people … it’s hard to keep arms and elbows pushed inwards towards body, trying to maintain your own space, there are bigger or taller people and it must deter them from travelling on planes much due to space/comfort issues.
Anyway, elbows are the least of my worries now I know my ankles could play havoc with me!