My approach is:

Switches replaced with Smart Switches where possible. Especially for overhead lights.

Lamps that are not controlled by a switch get a smart bulb. Hue white ambiance mostly. They just work, plus Hue has remotes that can be used to turn them on/off either from a table or you can usually surface mount them.

This.

I’ve moved from ST to HE but both would work well to accomplish what you want.

Just experienced this. Google killed Works with Nest and then Nest Secure. This prompted me to rethink my whole Smart Home strategy, dropping Google where possible, replacing SmartThings with Hubitat, and removing any device that wasn’t standards based (e.g. WiFi devices since k retractions are software based.)

I’ve had a more reliable system since and am actually able to enjoy Home Automation again.

Short (hah) of opening the box to verify it’s just a transformer and not some other system I don’t know.

But if the previous owner didn’t specifically exclude the Ring doorbell from the listing, they are required by most law (assuming you are US) to leave it. Even if they did exclude it, they are usually required to replace it with a working alternative. In either case you can take the cost of repair out of their escrow.

If you’re committed to Zigbee, the Inovelli Blue series are very nice. They are a bit pricier, but you get an extra scene button you can configure in HA, as well as the light bar that can be used for alerts and notifications.

If you can add a Zwave radio (USB dongle) to your HA install, you could go with Zooz. Also very nice, but less expensive than Inovelli. Zooz has options for scene controllers and plugs as well.