I mean, it takes 45+ minutes to caramelize onions. You can fry them for 10-20 minutes or so and get a pretty tasty result, but they aren't caramelized onions.
I have no idea why people say otherwise!
I watch a lot of cooking shows and the contestants (supposed to be professional chefs) will have 30 minutes to make a dish and they'll say "I will start out by caramelizing the onions." No you won't! You'd need more than your 30 minute cooking time to caramelize onions!
Onions can be caramelized in a slow cooker, as mentioned. They aren't as good as doing it on the stove properly but are good enough for the labor you save.
/rant
I do proper caramelized onions only about once a year because they are so tedious.