I also prefer boarding last and agree that in Europe it is never an issue.

Anyway had last week 6 domestic flights in the US and there it would have been not a good idea to board last.

About 20 pax had to gate check their bags and on two flights they IDBed the last two to board - one of them was a UA 1k and made a huge scene... To no avail. Busy flights, everybody wanted to get home for the holidays probably.

Interesting was how many people were boarding group 1 or 2, probably 75-80 percent of the pax and it felt more in 1 than in 2