it doesnt bro
Why d3, not d4 in this position?

It does. The chess.com engine might give you a low depth analysis, but try your own or check one online like Chessify.

It does. The chess.com engine might give you a low depth analysis, but try your own or check one online like Chessify.
d4 is useless because it can be en passanted and it gives up a pawn. d3 is recommended because it prevents Qg5, threatening a mate. It's also a pawn trade. d4 does stop the threat but it loses a pawn. you can take what I say with a grain of salt though because im a 600. hope this helps
Engines seem to prefer d3 here instead of d4. Why?