The problem with Wi-Fi is bandwidth and latency. A CG can be on a power pole tens of miles from a substation, using its own well, and having its own septic system.
However, Internet upstream access can get expensive because it requires a connection that not just handles a lot of traffic, but handles the traffic quickly, and usually one isn't going to get that unless the CG is sitting on a Verizon fiber run and Verizon chooses to split a connection from there, there isn't much a CG can do in the way of Wi-Fi, other than a relatively small connection.
Even with a good upstream, it takes a lot of equipment from routers to separate different areas into subnets, antennas powerful enough to get through the metal shells of most RVs, and other items such as an intrusion detection system (yes, there are those who will sit there and try hacking the CG just for grins since it gives them an anonymous drop for child pornography or other illegal stuff.)
The problem is that a CG faces two things. They can install all the network gear it takes to have a reliable signal and add a fee (which is going to take a while amortized by the relative few people using it), or have a bare-bones connection and not jack up rates.
Of course, the best solution would be to have all devices (laptop, tablet, printer, etc.) have the ability to use a LTE or 4G connection that is built in, so Wi-Fi is more of a nice thing to have than a must.