Catpcha was not invented to make the internet worse and solving one is not a real hurdle to you.
I'm not sure why you 'sat down for minutes' to solve any of them, you might just be really bad in comparison to a lot of other peoples.
Nonetheless, this helps YOU it makes YOUR experience better by making it harder for bots.
Have you ever seen a community killed by spam bots? You are probably quite happy that the amount of spam in comments etc. are as low as it is.