I agree, what ever Sony is doing is working wonders for them and there's no need to change there methods or strategy.
Sony isn't worried over smaller awards, I am sure of that, but to be fair, you can argue that same point with Nintendo and Xbox as they didn't compete with the main GOTY award due to they didn't participate in it either. Nintendo's game (Smash Bros) releases too late to be nominated in 2018 and Xbox's next big hitter isn't due out until 2019 and didn't release a major game in 2018 aside from a racing game that oddly enough wasn't nominated for GOTY considering its one of the better reviewed games in 2018.
GOTY isn't a genre to participate in. Any game if good enough can win GOTY.