Simple question, but I'll give some examples. I'm sure you have your own experiences.
I drive, a lot. Mostly the Northeastern USA, and into Canada. I have a GPS because I have the directional sense of a rusted bolt. I used a Tomtom One XXL for the last few years and liked it a lot. Finally it decided on its own to stop working so well. I can accept that; it's been out in the car during very hot humid summers and very cold winters. Tomtom has also stopped supporting it with new software or updated maps, because of "age and limited memory." (The devices, not mine.) So I purchased a Tomtom GO52 with Wi-Fi. With the One XXL once I was at a location, I could just press a few icons and add that location to my Custom POI folder which I could backup to my computer via USB. Not so with with the fancy GO52. I have to go use special software or a website to create and edit an OV2 file which I need to know the latitude and longitude coordinates of the location. Say what? To put them onto the device I have to put that file on my cell phone, and transfer wirelessly to to Tomtom. ::sigh::
I have an LG G6 as the above-mentioned cell phone. I've already cracked the camera glass. Apparently this is a common problem, because there are a few videos on how to replace the camera glass. Not one video, on LG's site, but several on youtube and such. I never had a problem like that on any phone, even my LG G4 which I had before. Which brings up the next point. I could use the G4 as a TV/DVD remote control. That feature is gone from the G6. I miss it.
I have a big glass window on my desktop computer, through which I can see fancy motherboard, ram and graphic card lighting. My mouse and keyboard also have a light show going on. They don't talk to each other. The mouse and keyboard are Corsair, so they use one program for controlling they LEDs and other options, while the motherboard and graphic card are bot Asus, and they use a different program. Neither of the lighting effect programs, work well. They are both supposed to turn off all lighting at shutdown, but over half the time at least one set of LEDs is on. ::sigh::
I live in a rural area so my internet sucks. My system monitor for my heating and cooling system connects to my wi-fi router so I can keep an eye on things when I'm away. It disconnects frequently, because it wants a better connection. It won't try to reconnect itself, because it, or the designers of it, are stupid.
That's enough for now. ::sigh::
The GPS thing seems like an example of progress for the sake of progress. Its also possible the marketing team identified wifi as a hot selling point for the upcoming season, and the engineers were basically forced to shoehorn in a reason that wifi was needed.
Second example is either LG trying to save money by cheaping out on components to save a buck, or planed obsolescence.
Fourth example just seems like bad engineering. It does seem strange that its disconnecting over ISP connectivity rather than a lost wifi signal. Have you tried putting your wifi box a little closer to the thermostat to see if that fixes the issue?