I started with Echo but ended up replacing it with Google Home because I like it so much more.
Google Home still requires you to use 3rd party apps but you are forced to set up the device in a location in your home/apartment. I can walk into my apartment and say "Ok Google, turn on all lights" and not have to worry about which brand of lights turn on.
When I used my Echo Dot my brother got me last Christmas, I had so many issues with the same command.
I think of our Echo as a command line and our Google homes as using a GUI.
BTW, GH is also a lot easier for old people has been my experience.
So it is a lot easier to use and especially for kids and older people.
You can talk to the GH more like you would talk to your wife.
I think of the Echo as using a command line and the GH a GUI.
The Google Home is generally better at ANSWERING QUESTIONS and providing information. Random queries that pop into your head a thousand times a day (e.g. Who starred in such-and-such movie? Who won the last time the Atlanta Falcons played the Carolina Panthers? etc).
Occasionally though, Alexa will surprise you by answering a question where Google flopped. Either way, like others in this thread, I now have both since they discounted them so low for the holidays. But for the Google, I get by with the "Mini" version... whereas I sprung for the full-size Amazon Echo because I use it for music, audiobooks, podcasts, etc and want the better sound.