Is it worth to C6 a character?

I’ve been bored thinking about this game today and wondering if it’s really worth getting a 5 star character to C6. I know it takes a lot of time and effort to save up for it, especially as a F2P player, but I want to hear what you guys think. If anyone here has C6ed a 5-star character, I wanna know your experience too. Such as if you have any regrets or if you think it was worth it.