The performance lag of Spacemacs was addressed by Doom Emacs ( https://github.com/hlissner/doom-emacs ). Have you tried Doom Emacs by any chance. After syncing everything, the performance is stellar in my opinion.
This collection page of Emacs packages: https://emacs.zeef.com contains only packages which are last updated at least 2 years ago, and it's already an impressive amount to me, which indicates that Emacs community is also very active, despite having - in IT terms- a very ancient editor.