This can happen to anyone buying only hardware and accepting zero control over the software part (which excludes things like right to repair/modify) 
As far as I know, there are no decent truly open options. Glad to be told I am wrong.
If you ask me this sucking google nest speaker product is not decent at all 
There definitely are some things that “suck” about the Google Nest ecosystem but the quality of the speakers and hubs themselves is actually half decent, especially considering what you pay upfront for them. The cost of your privacy does however, make them less attractive. Integration with HA is a snap (especially if you subscribe to NabuCasa).
I’ve been more or less satisfied with all my nest speakers and hubs, and I’ve had some of them for over 5 years now. They are used constantly all day long (music, tts, casting, google assistant, alarms, timers etc. etc.)
I do fear they are becoming victims of Google’s bad habit of trashing good things though.
Hey man, have you group speaker acting up lately? Mine been broken for as long as I remember. I can add them into group, however when I play to them through Spotify, sometimes only half of them play, sometimes 1/4, 3/4, etc.
I got sick of it and deleted the group and tried to create it again, and that time only 2 out of 6 speakers were shown to add.
It’s so frustating and I saw heaps of complain everywhere and there seems to be no fix.
All of my Google speaker groups are working as expected via both Home Assistant and natively.