Since the wallet data does not occupy any important space in my device,
I think each space is important but it is just that wallet data's can only consume less space, so we usually won't mind them inside our devices. Installing the software (wallet) maybe, is the ones that can be problem if we are also a fan of installing more software in our devices. It is still risky to leave a wallet data inside a device (except if it was a hardware wallet) because you know, cryptos are so popular now and hackers are doing their best to steal our data's. They can infect the device that we are using, with a virus or a malware.
I did not see any reason to delete the wallet details so I will just leave them there to remind me to avoid making same mistake twice. Deleting them might mean you can forget the pain of holding a bag of shitcoins, hence the possibility of repeating same mistakes. I have such collection of shitcoins that are practically dead with no hope of coming back. I regretted buying some of them even though they appeared very promising then. I will simply leave them in the wallet as there is nothing I can do about them.
Or you can also do this: Not buy any shit coin at all. That way you have no confusions or stress if what is the best thing that you must do. Also skip doing airdrops, especially those unknown ones, as this is also another way to get them.