I agree that python datetime objects are problematic, but for the opposite reason. It is tzinfo that is the sneaky disaster, the plain datetimes are fine.
Transparent timezone awareness always fail, unless you are 100% certain that a tzaware datetime object will remain uncoverted from the very top to the very bottom of the stack and all the way up again no matter who is reading and what they are doing.
For longterm minimization of pain, bugs and effort, you convert datetimes to UTC as early as possible and take them back to some localized version as late as possible (in the frontend, for a webapp, so that the backend never needs to know there is such a thing as timezones (except for separate validation and correction routines, since timezone definitions always end up being incorrect to some degree when you use them at scale)).
If the localization of the datetime is an essential aspect (such as the departure time of a ship leaving port), you store a UTC value together with a record of the location. Only at the latest possible moment of processing, should you do a lookup on the location data to make a local time.
Obviously, there will be exceptions to this rule. If you batch process billions of timestamps under a tight deadline and must do calculations in local time, it might make sense to have the values persisted localized.