Yes, ymmv (a lot). But alas buffer time is getting higher, not lower.
Yes, TSA is a big part of the problem. It's less "how long it took" and more "how long can it take". I've personally experienced those days where "TSA decided to go slow" and a couple hours disappears. The 5 minute days just make that worse.
Yes, the airport matters. If you're at some small regional it's no big deal. JFK or Atlanta etc is another thing entirely.
Yes, domestic or international matters. Yes, flying business class makes it faster. Yes signing up for "special status" makes things faster.
But airports are typically some drive away from city center (both ends, in traffic). Security and immigration both take time (often significant time.) Door to door time is easily 6 hours more than flight time.
I have _yet_ to hit a time where TSA can make multiple hours disappear. Precheck w/ touchless ID lines are virtually empty at most airports, the actual security screen itself is quite fast given almost nothing needs to be removed from your bag these days. I still tend to arrive early, but I don't mind getting work done at the airport, especially at a lounge - though I've arrived very close to departure other times and still make it to the gate with plenty to spare.
On international returns, both Global Entry or MPC lines are virtually empty when I arrive (SFO)
The worst part is international arrivals in foreign countries, where immigration can soak up a lot of time, and you have no choice but to stand in line. Luckily I don't have to fly internationally too many times a year.
>> I have _yet_ to hit a time where TSA can make multiple hours disappear.
Lucky you :). And I hope you stay lucky! Alas your experience is not universal.