It makes them soppier & reduces the size of their territories massively. So there much less likely to roam off & getting lost. Domestic cats have rubbish hunting skills because mum cat won't have taught them how to hunt, getting lost is a problem.
Other benefits are less fight wounds which cost a fecking fortune to treat, less antisocial behaviour like spraying urine & reduces spread of diseases spread from fights like cat AIDS.
In the uk most people neuter, microchip and vaccinate before letting them out. It's more "the done thing" over here though, we had an Irish lady on the litter tray who said much the same as yourself though.
Neutering can be done from a young age, shelters over here do it from 8 weeks but most vets wait until 4-5 months.
I think men are often against it for obvious reasons but it's not like their trouble nuts are coming off & they recover very quickly. Mine was up at 7am the next day pouncing on my toes. Stitches are internal and don't seem to bother them. It's cheaper to do boys than girls too.
My sil had a smashing little male kitten she refused to neuter because "he's not going to roam" and he was gone before 6 months after roaming off under a car 
, her current cats are neutered.
You could start a cultural revolution in Ireland of proper cat care. If no one routinely neuters I bet you've got higher feral cat rates than us and cat mortality. Cats reach 17-20yo here.