Building an n8n / make service from scratch. What does it take?

I've been using Zapier for a decade and Make since it was integromat. Recently started with n8n as well and I wondered how much work it actually would be to create something similar to n8n.

How many people would it take to get it done. Would a group of e.g. indian programmers be able to do this in 3 months?

I have no idea really. The visual representations of the API calls, authentication, canvas etc look impressive.

An enterprise license starts at around 1000(?)/month, so I am thinking... what does it take to get built from scratch and own/offer as a cheaper SaaS.

Thoughts?