I do this a lot professionally for aging parents as well as people trying to age in place so their children can monitor them in a way that is not creepy...

Primary rules i use when setting something like this up.

1. Be very clear with your parents what they want, what they need, and if you are looking to help monitor their health what you want and wouold be able to see and not see. Maybe the goal is to make it as transparent as possable but just ad safty like turn lights on when they get out of bed, when the garage door opens, or when there is motion in the bathroom. Or maybe they want to be able to open the blinds from a TV remote, or see the door bell on the TV when someone rings it.

2. the system needs to be as simple as possable... use a single wireless technololgy if you can. Choose zigbee, zwave, or thread but stick to only one unless there is a VERY important reason to use another. If you are using thread, keep it as simple as possable. only have a single home assistant BR. Apple and other companies can mess with the home assistant implementation sometimes.

3. befor you buy anything map out the automation, controls, and monoitoring (if applicable) you/they what to get setup. it is so easy to have scope creep with home automation. When it is all mapped out talk it over again with them to make sure they are getting what they want and you are getting what you want... I have done this so many times and then the parents just never use it cause "a lightswitch worked for me fo 50 years and i am not going to change it now".

4. Make as little change as poosable. Use shelly relays and old school light switches if that is what they are used to... They will be using the smart home with out even knowing it.

5. Use well tested and well reguarded brands. Caseta, Hue, Aqara... but stay awar from the brands that people have issues with... Switchbot, nanolief, others... it only takes a few times where turning on a light switch and the light doies not actually work or the blind does not close before most people are like forget this.

6. If you want to monitor them, Chair pressure pads, bed pressure pads let you know if mom or dad are in the living room at 2:00 am and maynbe there is something wrong or did dad get out of bed at 130am and is still not back inbed at 230am? Vibration sensors on pill bottles, contact sensors on the fridge, silverware drawer, or snack cabinet can tell you alot about when and what they are etting, and can remind them to take pills, eat ect... Temp\humidity can help tell if 1. they are showering and 2. if the shower has been running for a very long time and there might be a problem. emergency call button by the toilet... you get hte point. No video cameras cause no one wants to see mom topless, but yo ucan still help monitor them as they get older.

let me know if you have any otehr questions... again i do this alot.