Sure things might be getting easier but they’re certainly not easy.
-installed waterproof exterior socket, remotely controllable -installed various interior sockets -installed smart thermometer to control our little plant propagator
So far it seems to be a case of checking that the thing you are going to buy has a working HA integration program (which seem to be added on a fairly frequent basis) and then just adding it to the network. The only vaguely difficult thing I had to do was log in to my router homepage and change the wifi mode to allow the exterior socket to connect.
I'd much rather just not use Amazon/Google/etc where possible, as I don't like the feeling of being used.
[0] https://www.home-assistant.io/green [1] https://www.home-assistant.io/voice-pe/
Zigbee devices require more initial setup, you have to buy a dongle, install the Zigbee2mqtt addon and the mqtt integration, but once this is done adding a devices is a really simple process : you put the devices into pair mode and allow pairing for 90s in the Zigbee2mqtt page and rename your device to something useful.
But missing opinionated defaults, really, you still have to roll your own home/away/vacation solution. Creating a dashboard requires you to understand the meta of Home assistant which takes a lot of time.
People asking should I get PI or NUC every single day in the reddit. I am happy with my 2000lines long configuration file except scripts and automations. But it won't be easy for someone is not tech savvy.
If HA (which is a wonderful project) is your example of usable OSS software, then your bar is set lightyears away from what actual consumers need.