Right now they have a very strong cult following that continues to grow each day.
And once Red Velvet disbands in a few years it will make a spring board effect where f(x) interest will grow because Aespa will be SM only current girl group and they will be more linked to f(x) like Red Velvet was more linked to SNSD. And also more and more people realizing how much impact their music had on kpop and how much it shaped the sound of girl groups since.
So just a reminder that f(x) has been my ultimate group since 2015. I'm not on any bandwagon.