1 Big site or Few sites? Which is better for adsense?

[Dolev]

Hi everyone,
I have a site that is earning money since 2018,
The site has around 300 pages and the revenue is around $350-$600 per month

I'm planning to add new content to the site (something like 200 new pages)
The niche of the site is municipal services such as: paying parking tickets, postal code, etc
The new content is about business open hours, phone numbers, and addresses + municipal contact information

It can fit to my site but it can also be in new site from scratch (the competition in SERP is not high so that's not an issue)

My question is, should I add it to this site or should I create a new site?
I've heard that there is a roof for the money that site can make from adsense, so if i will create 2 sites it will be more profit than 1 big site.

What do you think guys?

[robzilla]

I've heard that there is a roof for the money that site can make from adsense

This is false. There's no imposed limit to how much a single site can make.

Add the content to the existing site if it makes sense, i.e. if it's a good fit.

[NickMNS]

I've heard that there is a roof for the money that site can make from adsense

You heard wrong, there is no earnings ceiling. If there were (hypothetically, because there isn't) at $350-$600 per month you are no where close to reaching it.

New websites need to be approved by AdSense, new pages added to an existing website do not.

[futureautomation]

Three hundred pages. That is quite a lot, so you've got a site going for about four years now. Gives a rough idea, of what a site needs now for adsense.