The export and import features are important for more than just your Garmin.
If you choose to use a mapping app that doesn't have an export feature, then you'd better like it, because you're stuck with that app for the rest of your days. No way to move your maps anywhere else.
An import feature is nice so you can read in maps that the RD sends you from another app. Without an import feature you either have to recreate his route or work in his app.