I got the iPad Mini 5 about six weeks ago and got one with the cell service. I got it so I wouldn't have to pre-download the maps. Even though I don't use them that often, I wanted to be able to use them when I need them.
I also got the cell service so I could use the iPad for anything else I want to do, even when I'm away from Wi-Fi.
Yes, the cell option costs money, one time, up-front. After that, however, you can make the cell service cost almost zero. Instead of putting it on my family cell plan (which would have been expensive), I purchased a 3-month 5 GB plan from T-Mobile for $30. So, for $10/month I get plenty of data. I also have a free VOIP number and, using a free app, I bonded that to the iPad so I can now use it to make and receive regular phone calls. So, for $10/month I get a device that can do anything, anywhere, and which has its own phone number which can make or receive phone calls, even when away from Wi-Fi.
Oh yes, it is a great device to use with my
Mavic 2 Pro.