Do you utilize your main/home domain page at all?

So it’s explained that you don’t need to worry about which template/style you use for your new website because you’ll be adding presale pages and using them as subdomain landing pages. (i.e. www.domain/subdomain presale page/.- folder) However, what do you do with your main page once they’re up and running? Can the viewer/traffic see your main page besides your presale page? Should we build up our main/home pages? (www.domain.com) Are they used for anything other than just a primary source for our presale landing pages? Hopefully, this makes sense.

I was wondering the same thing.
Also if we’re able to add other presell pages for different product niches. I have been trying to fit all the pieces together for weeks