The seats are assigned. People have been standing in line for 15 minutes now. Why on earth would anyone want to stand there, when they could just sit and wait until the line clears?
I understand wanting to get off a plane ASAP, but boarding? You just end up sitting on the plane, waiting for everyone else to get on.
Unless you need/like to stand before takeoff, I don't see the point. I don't mind if people do, as long as they are polite.
Bag space woes? It's real, but seriously see what you can do without. I fly for work at least once a month and I'm a pro one bagger for trips of 4 days or less; more if I'm doing summer weight clothes. It means I rewear things if they are clean and sometimes wash clothes in my hotel, but damn does it make travel easy.
Checked bag fees suck. Be the first to volunteer to gate check. I can only recall one flight in the last few months where an announcement wasn't made. The bag is waiting at the destination gate so you don't even have to handle bag claim. I do it every time I travel.