Many routers, what am I missing?

Working with an RV campground, so it's different from whatever is considered a 'standard' net. There are about a 100 sites and each site could have multiple devices. Gaming and streaming are probably not possible, but good access for everyone would be nice while connections between sites should be no easier than connection between two houses in the normal world. Here's the idea.

At the central building, with a Comcast modem of sufficient bandwidth, connect the modem Ethernet connection...

Many routers, what am I missing?