I wasn't making a claim about the historical importance of PGN. My issue is that it's become the de facto standard for distributing large collections of games,

I wasn't making a claim about the historical importance of PGN. My issue is that it's become the de facto standard for distributing large collections of games, which is inefficient and no longer necessary given the ubiquity of free chess programs. I agree that tokenizing isn't difficult. My pet peeve is about using SAN as a standardized format for feeding games to the computer. A naive encoding would use 6 bits for source square + 6 bits for destination square + 4 bits for promotion and other move flags. This fits a move in 2 bytes and is unambiguous. Compare that to SAN, which uses up to 7 bytes per move; requires knowledge of the board state and iteration over every legal source square; is potentially ambiguous if source rank/file isn't disambiguated properly; and adds extraneous information about captures and checks.