For the most part, if I am providing wifi in a place like that the only thing I want you to do is browse the web. I am not interested in your desire to run a torrent client, stream netflix, or do something else that consumes a significant amount of bandwidth. Most UDP applications are also rather poor when it comes to congestion control and in general do not play nice with the other children. These companies have better things to do than to provide IT support for people trying to use the wifi, so you block all UDP and force re-direct port 53 UDP (DNS lookups) to go to a resolver that you are going to provide in the DHCP lease. This also means that wireguard is not an option for most people if they are on these networks.