Just because something exists doesn't mean that there's any demand for it

To get anything even remotely close to Heyuri, you need to pray that a lot of stars align (in addition to putting a ton of work in) - we didn't just click our fingers and have a userbase appear. To just scratch the surface, you'll need to:
- be lucky enough that there's an exodus of users from another site you can provide a new roof for to kickstart things
- hope that some of those users become equally as passionate as you about your website and have them pour a crapton of effort into it over several years
- have the experience/skills to avoid all the various pitfalls and "people problems" that will come your way
etc.

>how can i make 20chan grow?
It's a bit like a newbie athlete asking how they can win an Olympic medal. People can tell you to tie your shoelaces properly and practice a lot, but there are many factors beyond your control that will (more than likely) prevent you from achieving what it is you want to achieve - unless you happen to be very, very lucky