Have I made a mistake buying my Apple HomePod?

I used to own a google home nest. It played my music through Spotify and I could put on the radio when I went out and it would play all day.

I’ve bought my HomePod, as I thought it would be simpler seen as I own an iPhone and apple laptop. However, it doesn’t seem to do either of these things.

if I try to play music or radio, it has to play through airplay on my phone and as soon as I leave the house, the music/radio stops. it drains my iPhone battery too.

How can I fix this or do I need to give up and go back to google?