I expect that to happen far less often.

Right. OP's is more an argument against time zones than Daylight Saving Time.

Honestly though, this should only be a problem for the small subset of embedded software without access to the Internet. If major OSes time zone databases are not able to be updated independently of the rest of the OS, that's kind of on them. We know time zone boundaries have been changing arbitrarily for decades, so shouldn't this be a solved problem?

Not against zones; I was hoping to shine a light on all the complexity around the TZDB, which is a mapping of zones to switchover times. Eg,

    $ zdump -v US/Eastern | grep 2020
    US/Eastern  Sun Mar  8 06:59:59 2020 UT = Sun Mar  8 01:59:59 2020 EST isdst=0 gmtoff=-18000
    US/Eastern  Sun Mar  8 07:00:00 2020 UT = Sun Mar  8 03:00:00 2020 EDT isdst=1 gmtoff=-14400
    US/Eastern  Sun Nov  1 05:59:59 2020 UT = Sun Nov  1 01:59:59 2020 EDT isdst=1 gmtoff=-14400
    US/Eastern  Sun Nov  1 06:00:00 2020 UT = Sun Nov  1 01:00:00 2020 EST isdst=0 gmtoff=-18000

If everyone simply picked a zone and stayed there, without the switching schedule above, you'd only need a mapping of zone to GMT offset and be done with it.

Ahh you’re right. Missed that!