"back in the day", it was hard to get anything, computers were expensive, electronics (except very basic) were hard to source, and prebuilt software (for whatever custom use) was non-existant.
Now, a microcontroller with wifi and bluetooth is <$5, a computer/server for running code is ~$50 (if you manage to find a raspberrypi, or a bit more for a micro pc), wireless interfaces (zigbee, bluetooth) are cheap, prebuilt code for sensors (tasmota, esphome,...) is very mature and stable, central management systems (home assistant,...) are stable and support pretty much everything...
The only problem I see is, that a lot of people have lost their tinkering capabilities and don't want to get their hands dirty compared to "back then" when a lot of stuff needed getting your hands dirty and more people went along the DIY path.