Typical programms for #FT8 and #JS8 both have an ALL.TXT feature. When activated, any text your computer ever decodes and anything ever sent will be written to that file.
Personally, I find that quite useful for certain research, so I activate it. Yes, over the years, this file can get somewhat large, but not too large for modern hard drives IMHO.
Asking the FT8 and/or JS8 users among you: How do you handle this?