Why can't I have my own boilerplate code (shipFast) like platform?

I am a web developer by profession and I would say am at an intermediate level of skill. Here is something I built as a first project of my own (https://thestartupmonks.com/). I am Currently exploring indie hackers and hoping to have my own micro SAAS.

I recently found this amazing person Marc Lou (https://marclou.com/) who has a lot of projects and one of which is shipFast (https://shipfa.st/) where he provides a nextjs boilerplate for people to have a sort of a code template with integrations like payments, emails, analytics etc. to begin with. (It also blows my mind, digital products which make money can be really simple yet so impressive)

Genuine question, how would this be any different if I do the same with the Nodejs Backend, Vanilla HTML/CSS, and add all the important integrations with it ?. I even found another person who is doing the same for swiftUI apps (https://www.shipthat.app/).

I mean, I understand one problem would be marketing/sales, reach to audience etc. but technically why would person X buy shipFast and not my code?

Thanks for the responses in advance.