if your talking ar15 its because everyone likes different ones so they often leave them off and let you pick your poison.
most bolt guns dont come with them and havent for decades because the ones that did people just tossed the sights or cut em off and put scopes on. so the gun makers said f-it why put on something most folks dont want save some production costs.
Some of the old rifles had really good quick disconnects with dead on zero return. In addition they had great iron sights. That's something you just don't see anymore, but it would be nice.
My buddies thought I was crazy for wanting iron sights on a long range rifle. Never the less I still wanted iron sights just in case. Then I noticed an odd looking block on the end of the barrel on the M24. After further investigation I learned that was for the quick disconnect palma sights. It was nice to know that I wasn't the only one that thought iron sights should be on a long range gun just in case.
It may depend on where you live. I enjoy shooting my Sharps 45-110 with its iron sights. However most of the hunting in the West is over miles of Sage Brush with no trees. This type of shooting is more often at 250 Yds. plus. The iron sights at these ranges are a real disadvantage for shot placement.
I to love iron sights, here in ky where I hunt you'd be lucky to have a 200 yard shot. Most of the high powered rifles I own are mil surplus just because they always have iron sights, even my shotgun has military style sights along with a red dot.
I do shoot scoped rifles but only at distance most of my target shooting is done with irons out to 100 yards, I bought some scope rings called iron sighters they have a section cut out so you can see your sights along with your scope so you can use both I use them on my 7mm mag and it works well enough.
Buying a gun without sights is like buying an un-sharpend knife, useless for anything but admiring!
I was never a fan of glass because its just too finicky for my likes but I was Anti Armor and a hunter not a Sniper nor a target shooter. Neither my Military service nor my Hunting ever proved me wrong on that. Im not the best shot but most everything I shoot is ventilated well or dies rather quickly, thats what matters!
Nothing like a Battlesight Zero on an m16 to get you on target quickly and NY isnt big range country so scopes really dont help here much unless your on a bench. Besides, one trek through thick brush and the scopes no longer aligned anyways.
The sights on an M16 are about as accurate as anyone could ask for if used like they should be. 40 out of 40 on a qual range is very acceptable and ive seen it happen often and done it myself a few times. Those in Basic Tng that never fired before shot better on average than those of us with lots of civilian shooting under our belts, because we wouldn't listen, those with no experience listened carefully and shot well right out of the gate.
The sight picture is not the same, if you try to use them like the old Iron sights, your gonna suck bad at it, better get a scope! I would not buy a weapon without Iron Sights, I like my guns complete out of the package!
The reason the guns are not being made with fixed iron sights is because most people have been doing that thing your momma told you not to do or you would go blind. So now we all can't see worth a dam and need scopes to make up for our self gratification when momma was not looking.