That's part of it, of course, but their are other reasons.
Assuming I won't need contact lenses or glasses for the next 15 years, I will save money (paying GBP300 per year just for contact lenses and solutions at the moment).
As some may have picked up I get allergic reactions to metals with nickle which has caused bad problems in the past due to glasses.
I also play a bit of sport, and it is much better in that regard. also want to sart swimming, but that is not a good idea with contact lenses.
Other things are pure laziness - sometimes if i've come home and taken out the contact lenses, I won't go out again because I can't be bothered to put the lenses back in, and I don't really like wearing glasses, and rarely outside of home.
There are other considerations, going out to clubs etc and wearing contacts all day make them get dry towards the end of the day, and staying over someone's place without preparation means sleeping with contact lenses in; definitely not a fun experience. I remember once falling asleep at a Greyhound bus station in mid-west America and waking up being unable to see, contact lenses had dried out in my eyes and I kept blinking rapidly. I took them out without washing my hands that time- not a good thing!