Where can I run into pitfalls when using an Android emulator over a real device for app development?

I want to get into developing apps for Android because of its large userbase. However, at the moment I do not have a smartphone. I'm also not too keen on getting and Android phone in the future.

What problems could I encounter when developing apps for Android solely using an emulator? I could use my parents' Android phones for the occasional testing, but will an emulator prove sufficient otherwise? Furthermore, is it possible to set up an Android Virtual Device with low-end hardware on my computer to test out apps with low-end phones?

note0: I do not plan on developing apps which require use of the phone's sensors (such as gyros, GPS, etc.) I only plan on developing apps which require internet access for API calls and perhaps microphone usage (I can't give away too many details right now ;) )

note1: I know this question has been asked before on stackoverflow (albeit 4 years ago). However, I feel it is important to revisit the question because emulators, hardware, and Android itself have changed enormously in the last few years.