Or a statement about the annual carbon budget?

Which is also why we can't have faster planes. It's not good for fuel economy.

There is some 'startup' trying to bring modern versions of concorde planes, not really grokking the reasons it went out of business it seems.

As if rich people are not universally hated enough, lets show off to everybody by flying marginally faster and polluting way more in super cramped very loud tubes. Some technical challenges can be maybe addressed these days but not all of them. Unless folks fly half around the world time spent on airports takes away massive chunk of overall flight time anyway.