I've never been on a flight that didn't take a long time to get through all the corridors, wait for plane, fly and then walk the corridors at the other end not take hours. Even short haul from smaller London airports to a Spanish city.
The system is set up to take up a significant amount of time.
It can be done, most airports are just amazingly inefficient. No idea why that is.
The last major airport to be built in the US was DEN in 1995.
Funnelling everyone through such a small number sounds efficient for the airport, but isn't from a travellers perspective. Heathrow and Gatwick, are massive.
I've long ago realised that cost, comfort, and commute are like the project management triangle, you can pick two: Short commute in a comfortable home is expensive, cheap home with a short commute is uncomfortable, and cheap and comfortable home means a long commute.
This is why work from home is so valuable, in that you can live comfortably and affordably (say, a three bedroom apartment in Barcelona) without the cost or time spent commuting.