A [very] brief look at the in-store WiFi offered by Apple in the Festival Place shopping centre in Basingstoke.
The Apple WiFi experience is the gold standard in public WiFi deployments. They collect no data (top GDPR compliance) and they provide a very fast connection.
When the store is busy, the connection is shared with other users and I image that it will slow down considerably, however it offers great speed.
This is an example of how great a service can be when it is delivered as part of a wider requirement. Apple stores need a lot bandwidth via wireless in store, because customers need to back up their devices and want to try out phones and computers. It is therefore necessary to make it easily available to customers.
Interestingly, by collecting no data at all, Apple have no responsibility to users to keep their data safe. As Apple are not interested in selling your data, and they [probably] already have your contact details, why bother? As far as Apple are concerned, it is NOT a legal requirement to collect user data.