People will often choose to not have a countdown.
I buy a smoke alarm with a fixed 10 year life to avoid battery replacement. Others buy models with replaceable batteries, still others install wired alarms.
You should disclose the lifecycle at sale so consumers can make a decision. I’ve been in the computing infrastructure business for many years - I can model out the expected life and cost structure for all of my gear.
Deviating from your argument, but 10y battery life is a EU regulation. In some EU countries, you cannot rent out a living space without smoke alarm that has a 10y battery in it, even if it’s wired in. If you’re looking for a high quality smoke alarm (ability to trigger on different types of fires and certified for EU) I failed to find one that came with a replacement battery, and only a few that are wired in, all of which will have a 10y lasting battery. The more expensive units do connect with internet/vendor and can do smart stuff like call fire department etc, you’re right that there’s a choice. But, the choice is very limited.
I’m not sure that an average consumer is even aware that some smoke alarm sensors degrade with time, or not trigger at all types of fires, there is probably some logic in forced unit replacement every decade.
That’s interesting. There is a certain logic to a regular maintenance cycle for high impact items.
It may be an example of an unintended consequence - to be fair to the Nest people, when you’re releasing a new product, you may not be thinking of end of life. Today we should be stamping a support date on them - Google is pretty good about this with Chromebooks, for example.
The forced upgrade assumes that sensor technology will improve between purchases.