I feel like this is a fairly common opinion. Also, I believe they do have to after some point; not sure how the airline decides though?

It’s got to do with calculating the amount of fuel for the plane. More weight requires more fuel.

No it isn’t. Not in large airplanes. The typical takeoff weight of an A320 is in the neighborhood of 50-70 tons. The pilots do not give a shit if a few passengers weigh a couple 100kg more than the average, and that’s a narrow body. A couple PAX being grosly obese on a widebody, with typical takeoff weights in excess of 100 tons, is even more negligible.

Fuel calculations and weight&balance is calculated based on assumed average weights for men, women and children.

You’re using actual reasoning, while dismissing my edit of corporate greed reasoning. You better believe, especially in capitalist USA, they’d just as soon charge you $10 a fart if they could…

I mean they literally DON’T charge you for extra cabin weight, or body weight, even if they could. Most airlines don’t even put weight limits on cabin luggage, only size limits. And even those that have weight limits, in my experience, very rarely enforce them. Generally, only size is enforced for hand luggage.

And they only charge overweight people double if they’re so large they physically block more than one seat, which imo is fine. If you need more than seat, it’s perfectly fine to expect you to pay for that extra seat. It has absolutely nothing whatsoever to do with either excessive greed OR mass/fuel issues.

I won’t lie, I’ve never flown before in my life.

I only lived within walking distance of two airports, one of them an international airport, and the other lightweight airport flew their planes right over our house.

So I’ll pretend I don’t know anything if that makes you happy. Those of us on the ground learn the real rules when planes start crashing in your back yard…

Commercial jet liners are the safest mode of transport by a massive margin, and several orders of magnitude more safe than anything that is on a public road.

Don’t see you raging against buses or taxis here.