If I was going to do more automation I would consider moving away from Google. Since their smart speakers are 90% of what we have automated there doesn't seem to be a point now.
To be honest the best "home automation" we have are two sets of these Wireless Remote Controls that are dumb automation. Just a remote to turn things on and off. Its been the most reliable thing and simplies thing to set up so far.
What was your problems with their Zigbee Hub? I know I will need one but want something that is plug and play. We just had a new baby so I don't have forever to play around with setting up automations