then you may be fine with that information loss. But is is one nevertheless.

But in applications where it matters, you make sure you know the source timezone where the data enters your system.

E.g. When comparing temperature charts from different places in different timezones, you may want to show them in a way that "noon local time" is on the same place of the X-axis in both cases.

Or more usual: I keep a log of what I do during a day. If I now move to another timezone and want to look at the log, I don't want the times shown in my current timezone. I want the timezone I was in back then.