I never really had toxic friends, just kinda selfish ones who sucked at maintaining their end of the relationship, thus communication died out when I had enough of always having to be the one to initiate contact. If they can't be assed to talk to me on their own, they didn't care that much to begin with. I can think back fondly on the good times we had without particularly missing them as people.
Similarly, I sometimes miss the good moments in my relationships with my family, who very much is toxic and who I don't plan on keeping in touch with once I finally move out. Jokes they made, little traditions around holidays, etc... I can keep those things without keeping those people, but it will always sting just a little bit.
It sucks having no family and very few friends. I can see why you'd sort of miss even the bad ones, especially if you do have at least some fond memories with them. That only seems natural. But hopefully you can make some new memories with better people in the future.