As has already been stated, you have a flock protector, a judge to settle disputes, eye candy for your yard and a breeder of new chicks. You also have a built in alarm system if anything tries to get to your hens day or night. They will also let you know when someone is near your home. Day or night. I have a bear problem where I live and my roo Percy always lets me know when he's around sometimes even before my dog knows.
The cons, as already stated, too many roosters will cause problems with your girls. Some of my poor hens are still bare backed from a roo I finally had to cull. He was a rape bird and nothing would stop him from it. Egg production dropped down to nothing with 8 hens because of the problems.
I currently have 3 roosters than run with the girls and 2 that are in a 'Boy's Club' pen. I have 14 girls and right now two of the roos are young enough that no problems have started. If and when they do, I will add the 2 young ones to the pen, with the other 2 and just keep them for breeding when it is time for more chicks. I hatched these roosters and want to keep them. The cost of feed is going up and who knows where it will bottom out. Feeding a rooster or more than one, if you are not going to hatch the eggs, doesn't make much sense. Another con, roosters crow when they want, day or night. I live in the woods and there are no lights after 11:30 pm., doesn't matter. If Percy feels like crowing or something is up, he will crow. Even if it's just the tree frogs singing.
One more con, not all roosters are user friendly. Their job, as they see it, is to take care of their girls. It's wired into them from birth. Some, like Percy, will take it into their heads that you are a threat or he's feeling quite macho and try to attack you. He will eat out of my hand but sometimes he gets into a mood where he thinks he is dominant over me. Not allowed here. There have been many times when I have had to use a broom on Percy to get him to see things my way. Sad but true. Now all I have to do is show him the broom and he stops his puffing and settles down right away.
Final word, I would not get rid of my roosters, no matter the cost of feed or the moods they sometimes get into. It may be a love/hate relationship sometimes but in the end it is very well worth it. Just my 2 cents.