LSRFM seems to be a lot closer. If LSRFM were disbanded, i think all five would agree to re-unite at a different label, dont think it would even be a question.
I still dont know why only 3 out of 6 Gfriend members became Viviz
Gfriend were solid performers, plus Mago is a literal 10 out of 10, but LSRFM are stage demons, they might be the best performing GG in Kpop today.
Most likely due to legal reasons because there was no guarantee that HYBE/Source Music would allow them rights to the GFRIEND name/brand. Also, they probably just wanted to go their own paths in the meantime. It wasn't until last year that Source Music's application to trademark the GFRIEND name was declined multiple times, which was WAY after all the members already left and started their own careers.