I love how the receiving end's security works as well. You stuff everybody into a big room, hot, humid, badly ventilated (presumably that was the local climate, but still). You mix everyone from everywhere, and make them wait in line for hours, VERY close to one another. Breathing on eachother. Some passengers obviously ill, coughing and sneezing. You make everyone stand around like this for hours.

The video playing ? "we are working so you won't get hit by diseases"

There must be some real sadists working at government airport regulators.

Why not go for broke and do both?

It seems harder to be inconspicuous with 40 lbs of explosives taped to your body than to wheel it around in a carry-on bag.

Have you seen the size of the average American? Throw on a staypuff marshmallow parka and you'd look like 40% of travelers this past week

Sure, you won't look larger than the average American, but they grew that size over months or years and move naturally with the extra weight.

Strap on 20 - 40 lbs of extra weight and you won't move naturally anymore, at least without lots of training.

If your goal is just to kill as many people as possible (rather than, e.g., needing the plane for smuggling or hijacking), surely there are enough events where people are packed together that it could be done with or without TSA lines? Take any music event for instance - the standing area will be packed, and security will be minimal if any (last time I went to Wembley Arena the bag search was pointless - I had a jacket in mine that completely obscured the bag contents, and there could easily have been an explosive device concealed below. FWIW, this was only a few months after the Bataclan attack, and the venue had specifically said to arrive early due to increased security).

The security lines are definitely a softer target than needing to get on the plane, but soft targets are easy to find anyway.

and to add insult, everyone will die barefoot while the dammed terrorist can have their shoes on still.