Surprised there is no mention of IKEA. It's affordable, standard-compatible, and last time I checked, was among the most secure: partly because of the reputational risk for IKEA, (and also because it's the right thing to do!) they must keep it updated and supported for a long time.
Their lights are nice, but their motion sensor drains the battery in 2 months or so. Eventually I figured out that I could control the IKEA lights via Philips Hue, so I could switch to a Hue sensor which is already lasting a few years.
In general, Philips Hue / Signify is very reliable in my experience, though expensive.
I've got a bunch of Hue motion sensors (which have lux and temperature sensors too btw). I've replaced the batteries (2xAAA you can grab at any store) exactly once during the 5 years so I've had them.
There is something odd about the battery life on the Ikea motion sensor.
I use it in our bathroom and it's activated multiple times per day.
The first battery lasted about 3 months but the second battery has been going for over a year.
There are some reddit threads but I never got a clear answer.
IKEA devices have a tendency to drop off and need repairing. Every power outage would require repairing half of my lights. Their switches and motion sensors chew through batteries.
Their color bulbs are disappointing in both lumens and color reproduction. Their white-scale bulbs max out at 4000k, when most daylight bulbs are 5000k.
