Products are often cheap enough that the labor costs are too high compared to getting a new unit. It would generally work for appliances that are built into a house or hard to transport because then the relative cost would be offset by the cost of labor to remove and install a replacement.
For example, people generally wouldn’t do this for a TV when they can get a decent replacement for $300 new.
It would probably only work in countries where services are cheaper than buying new.
For example in south america is is common to get shoes repaired or customized. Clothing altered to fit or be repaired etc. In the US it really only makes sense if that article of clothing is > $200-300. Its pretty hard around me to find a tailor that will do much of anything more than basic hemming for less than $75-100. whereas in south america it would only cost me around $5 to get something altered or a shoe repaired.
I would get something altered about once a month in south america. In the US, maybe once every couple years.
You write "Products are often cheap enough" as if that is a law of nature — it isn't. That is the result of a global production chain that has valued efficiency of production over nearly everything else. This is currently changed, now national interests became more important in the most careless way possible.
There are many examples of countries where old technology has to be maintained because the new is unavailable or unaffordable.
Presumably the "decent replacement" will also be too smart for their own good and there will be people who will pay extra on purchase for a "de-smarted" device.
Speaking of which, I shudder to think what will happen if my current TV ever breaks. Would getting a "smart" TV and physically removing the wifi help?
My prediction is that more devices will start to come with an eSIM that phones home and downloads more ads or uploads user data whether you give it WiFi access or not.
Amazon Sidewalk can also be used - it automatically finds devices on other networks (like your next-door neighbor) and sends data through their devices in case you don't connect your device to your own network.
Have you ever seen TV not connected to the Internets? Some models refuse to work with "no free storage" alert if it has spywared too much data about the used (used is any user of proprietary sw). When the used connects the snoop-TV to the network it of course unloads the data.
I still have a dumb monitor that costs more than a TV that would have a larger diameter with an HTPC that is really just a regular Linux install and that runs open source software on it. Which software has changed over the years, as has what kind of "TV" I get on it, from actually having a cable TV tuner in there to all streaming or local files. Over that time frame, it has become increasingly harder to get things to work "properly".
As in, yes there are caveats to this of course. Like there's no Netflix (/insert your favourite streaming service) app for it and you probably can't get 4k and/or surround sound from in-browser. As in, they're intentionally making the experience of people actually paying money to them worse.
It doesn't need to be lifetime, only as long as devices are supported. Also, electricity meters makers somehow solved this problem. I am sure a subscription won't be expensive if the device doesn't use too much data. Also the device maker can pay with collected data or advertisement.
Start with luxury items. You're right, not many people would pay $500 for a dumbed down device when they can buy a smart device for $300. But, I know for a fact that there are enough people that would pay $5000 for a $3000 tv if it had the default OS removed and replaced with something sane.
A lot of things are about to become very, very expensive in the US, if Trump isn't stopped somehow. If there's a silver lining, it's that people are going to want to hang on to what they have and keep it working.
For example, people generally wouldn’t do this for a TV when they can get a decent replacement for $300 new.