@2184a19c I don't think there would be "one" semantic/pragmatic factor here. There's also the question of the many Englishes, and the many contexts it's used in (/style/register). But I don't think it's controversial to call the use of "I" here archaic-sounding. 

 @65e9a77e Thank you. Yes, it is archaic *sounding* at least. 

 @2184a19c And there are wildly different conventions around spoken and written language! At least in Danish, the norms think people think work, are not only outdated but also stated way too strongly 

 @65e9a77e Yes, there are. And in the same way, there are a helluva lot of English-language prescriptivists.