Once I became an old fart, I started seeing these lines as a sign to move on. The question in my mind (at any age) was always "is the place worth waiting in line for?" But these days, I already know from years of experience that the answer is very likely "no".
Skipping the line has improved my nights out, though, because in looking for an alternative, I frequently find hidden gems and can enjoy them before the rest of the city discovers them.
This has been a process for me. I still occasionally succumb to the silliness, but for the most part when I see a line, my reaction is, "meh, I'm hungry/thirsty now; let's go somewhere else". One thing that's telling is that some of the places I already know I really enjoy rarely have lines or are completely busy.
And absolutely agree that you often find hidden gems that way. A lack of a line will often just mean the business is too inexperienced or honest to use some of the psychological manipulation practices the GP talks about.
Totally tangential but follow-ups on that psychology:
* some people would walk in and see the still mostly-empty bar and get fed up that they waited in line for "nothing". This was surprisingly few people though.
* some people would ask and buy just about any explanation - "oh that guy is new and still learning", "we had someone get in on a fake ID and got a fine the other day so the guys are just being careful" or whatever and the people would be glad they got in early to get a good spot.
* sometimes we'd slow down the bar staff a bit too so that there was a line to buy drinks and people were happier that they had to wait in line again - confirming their bias that they must have gotten in at the start of the rush.
* some people were wise to the scam and everyone who called us on it thought it was great. They often offered to have their buddies come through the line a few times in exchange for a free drink.
* for some reason when you let your buddies, regulars and off-shift staff cut the line and get in quick, the rest of the folks seemed more willing to wait in the line.
tl; dr - group psychology of humans is wierd.