Interesting question, I know. For me personally the answer is no - I have not ever regretted having gotten into bitcoin, despite having spent hundreds and hundreds of hours researching the topic. It's always been an interesting ride.
But I have a friend who got scammed and he regrets having had anything to do with crypto in the first place. It's pretty sad but there's nothing I can do about it. I even offered giving him half of the amount he lost from my own crypto stash (mind you I am not rich) but he's so scared that he's not interested any longer...
Well, the bitcoin price in the cryptocurrency market is suck now indeed. But despite the losses, i gained many profits from joining cryptocurrency more than i gained losses. So, i won't regret for joining in cryptocurrency world. Even if you are having much losses, you won't regret your action for joining cryptocurrency as long you can afford your money to lose when you buy coins.