You perhaps need to understand the fundamental differences between WiFi+Cellular and WiFi Only models of iPad.
It is quite true in that only WiFi+Cellular models of iPad have GNSS/GPS capabilities - this being a function of the iPad Cellular chipset. By contrast, WiFi Only models of iPad have no GPS capabilities with which iPad Location Services can derive location. This fundamental difference may significantly impact your ability to use mapping Apps - or other Apps that require accurate or real-time positioning data (e.g., a moving map). Be aware that when using a mobile phone’s hotspot, the phone does not share GPS information derived from its own positioning capabilities.
WiFi Only iPad models can only “infer” their location from a [crowdsourced] database lookup of neighbouring WiFi networks for which the geographic location is known, or the geographic location of the public IP address derived from its active network connection. For static applications in urban locations, where the location of IP public IP addresses and WiFi networks are known, an “inferred” location can be relatively accurate. However, in rural locations, or when using a Cellular/Satellite/VPN connection, location accuracy of an inferred location [if it works at all] may be very inaccurate. If no network connection is available, then location services won't work.
All this has significant implications for non-static mapping and similar applications. If you need to have moving maps, or have future flexibility to do so, you may need to consider a WiFi+Cellular model of iPad. Choosing a cellular model does not commit you to adding a cellular service plan for the iPad, but ensures that you have immediate access to GPS/GNSS positioning services.
While WiFi Only iPads cannot themselves derive location using GPS, any model of iPad can access precise GPS-derived location data using a suitable external GNSS/GPS receiver. These are often used in marine, aviation and vehicular applications - and can be either directly connected via Lightning or via Bluetooth. There are various third-party manufacturers, of which two popular options are BadElf and Garmin GLO.
Many iPad owners choose a WiFi+Cellular model in preference to a WiFi Only iPad simply to benefit from the ability to access precise location data both with an active network connection (via WiFi with an internet connection or Cellular) - or without any type of network connection. Many have no immediate intention of using Cellular, but maintain the flexibility to do so should the need arise.
