Very rare people use the postal service not only because it is notorious for misrouting parcels and letters somehow they are costly if you avail of the VIP service.
Not sure if that is the thing with the postal offices as in our country the National post building is quite old too! Sure they renovate but they opted already with the usual mail route. Stamps are for collectors only and don't serve the purpose that much anymore.
Well, there are official papers that need to be sent and you must use postal services. Stamps are still a thing, not everything is digital, but the for of the stamp matters less. What matters more is the date as in case of official deadlines, you need evidence.
I completely forgot about that paperwork, especially the government files that need signatories.
Agree that not all can still be transacted digitally. I wish it was but it isn't the case yet.