The short answer is not. Although GPS devices with maps and routing existed before social media exploded and Garmin were the industry leaders in this, it no longer makes commercial sense to build products based on this model.
So where does that leave someone who does not want to leave a footprint on the internet - fundamentally you are stuck in limbo, no one wants to provide you a modern product.
The solution is rather than avoid online registration, set up an internet presence for just that one purpose. Open as gmail account "BobsGarminAccount.gmail.com" and sign in with this when using Garmin. You will have the advantage of working within the system, getting updates etc, while remaining (relatively) anonymous.
Maintaining a separate digital identity for this purpose can be difficult, but it is, theoretically possible. Avoiding logging into the shadow identity account from your normal pc or phone/home WiFi/regular Starbucks WiFi AP might be required, and may not be practical, but it is possible.