solid openings to counter 1.d4 as black

What is statistically the most popular is hogwash. It is pretty much well known that the best responses to 1.d4 are 1...d5, 1...Nf6, 1...f5, and 1...e6.

1... f5 scores 43/57 across 27,500 games in the Lichess masters database.
1... d6 scores 46.5/53.5 across 27,500 games in the same database.
1... g6 scores 46/54 across 24,000 games in the same database.

For reference, 1... Nf6 is scoring 45.5/54.5, 1... d5 is scoring 44/56 with a massive amount of draws, and 1... e6 is scoring 45/55.

I would rate 1... f5 as worse than both 1... d6 and 1... g6 as it scores 3-3.5 points worse at the same amount of games.

It changes depending on rating, it is rare for me to face something from the Queen's Indian/Nimzo Indian/Bogo-Indian family of openings from players rated lower than me but it is a lot more common when I face stronger players. 1...d5 is what I see most often, followed by the King's Indian Defense. The Albin countergambit I see quite often too from lower rated players. YouTube videos probably are heavily influencing what newer players choose to play now.