You never know if it is an upgrade until the factory gun has run a bunch of ammo, say 500 rounds without a glitch, then you know the gun fits the design specs and you have a blue print. Only then do you have a clue if some alleged upgrade is actually an upgrade.
For example, you take new gun with a 5 pound trigger pull and buy a kit to make it a 4 pound trigger pull. Did you upgrade? You have no clue until that gun is broken in.
Second, with trigger pulls there is a massive amount of hype perhaps more so that any other gun part. If you change the pull from 5 pounds to 4 pounds, are you good enough of a shooter to actually prove that your shooting is better? Unless a factory trigger does not break in at say 500 rounds, you may just be wasting money. You can NEVER just feel a trigger and know it will improve shooting. What you feel is lesser pressure but that does not mean more accurasy. Just saying. Triggers matter in things like ARs, handguns not so much.
They only matter on the range, not in your living room.
Your opinion, certainly welcome to it.
Trigger weight is only one reason I change them out early. Take up, break, reset are others.
Yes, break can clean up/smooth out with use. 100% agree. Take up and reset do not.
Am I a comp level shooter? No. Can I shoot more accurately with a lighter pull and cleaner break/reset?
Yes.
I take the time to clean up factory trigger contact points, typically striker, trigger bar, sear, striker block, etc. Which, I'd agree, can smooth in/break in with time.
I'd argue triggers in handguns make a bigger difference in pistols than they do ARs/rifles.
Why?
With a Rifle you have 3-4 touch points (hands separated, shoulder, cheek weld).
Pistol, two, both hands, over the top of each other.
Sight picture… a few inches, vs… more.
But I spend a lot of time shooting and practicing. I know what I like, I know what I shoot well.
Certainly, I can't speak for everyone else. However, neither can you.
As you said, they do only matter on the range, I do agree 100% there.
I'd also add, not until I get through 500 rounds through 2-3 mags with all different ammo, including at least 50 to 100 rounds of actual self defense rounds, without any malfunctions, do I put a pistol into my carry rotation.