Well mainly because I have a small sedan that I already have to strap down surfboards on the roof of. Want the convenience of being able to fold it up and throw it in my car/friend's cars etc. Mainly going to using this bike for going to the beach and for mild trail riding. Will look into getting a non-foldable e-bike in the future.
When I was researching folding bikes I had come to the conclusion the Sondors Fold XS had the best design and quality. There was also a lot of praise from the review on this website regarding the programming of the cadence sensor. Well worth a watch if you haven't already.
The Rad bike comes with mechanical disc brakes which may be fine for some but that was a deal breaker for me. Ebikes are heavy and can easily reach speeds of 20+ mph. The added brake assistance of hydraulic brakes just seems like a no brainer for me
Try the brand specific sections on this forum. A lot of great information about these bikes can be found there.
Also just want to point out the Lectric XP is constantly considered the best folding bike for the money. It's currently $899 and can do class 2 and class 3. Class 3 is somewhat rare for folding ebikes. If money is a high priority and you can make some concessions like front suspension or battery size then this might be the bike for you.