This isn't universally true. If I had my Bible in front of me I could probably rattle off a half a dozen reload recipes that were slower than normal that actually increased the SD and likely decreased the accuracy. There are also numerous Rifle and Pistol loads where is hot as you can go feasibly is actually the best round it all depends on what powder projectile and application you're using.
People say this constantly and I have no idea what it means because it's not quantifiable usually in any meaningful way what do you mean you wear out of recoil spring 200 round slower?

I think mostly it's a bunch of stuff people tell themselves to make themselves feel good about making mouse farts. I bought guns to shoot them not pull a soft shoe routine. I only ever damaged one gun with hot ammunition and I really didn't care about it.... that's when I was loading up 920 FPS plus 230gr Thumpers for my pin gun... somehow it bent the guide rod a little bit I just sanded it down a tiny bit and it's good to go for another God knows how many thousand rounds...

honestly I don't even know if it was the hot ammo because that gun took many thousand more rounds before I stopped using it and even today it still will lay bullets on top of each other at 25-35 ft.
Don't get me wrong most farts have useful applications but to make them as a matter of course it's just insane I don't really get why people are so obsessed with producing mouse farts as reloads. Sure i made a 750 fps light pin load and I thought it was marginally useful for some applications (you could run the gun very fast with such a load... but I also could run that gun without having to respring it in the process these guys who make mouse farts that are so slow where the stock Springs are too heavy for the load it's just f****** ridiculous to me.
By default im factory or factory plus. I even chastize lots of commercial ammo for being too weak. I don't really like shooting ammo that's not reflective of the reaal world unless there's a great reason for it.
You would have an aneurysm if you came to a pin shoot in the mid 2000s then. A lot of us were lobbing golden saber 185 +P at pins 25ft away because you could get them for like $20/50rds. 1170fps sure moves the pins well.

also honestly I would have bought hollow points to shoot for target shooting for 45 even working them up it's reloads because a lot of times you could actually get the load to be more accurate not to mention they work a little bit better on pins because the edge of the jhp might grab the skin of the pin and help rip it off the table...