Michael nailed it.
Any network application is limited by its lowest capacity component . At a campground that component is always going to be the connection ( a MODEM) to their ISP, or internet service provider. In urban areas ISP can deliver 100-300 Mbps (million bits per second). In rural areas a FAST internet connection might be 10 Mbps. A Netflix user consumes about 5 Mbps. Do the math. A 10 Mbps connection would support only two Netflix users, and they would likely have buffering issues. Everyone else would have trouble downloading an email.
To put it in a way most RVers would understand, it would be like trying to run two A/C units and a microwave at the same time on a 30 amp circuit.
I suppose it’s possible that a Resort campground might purchase a commercial grade internet connection, but proper etiquette would require that you confirm that before you start streaming.