Where are the opening trends heading at the start of the decade? Nearly every era has its opening trends like at the beginning of the millennia the Berlin started to become the trend and so much that e4 was starting to be avoided. With the 2018 world chess championship and Carlsen scoring, numerous wins with it the Sveshnikov is getting into fashion again. Even in the old days of Capablanca and Alekhine practically only Queens Gambit declines and Ruy Lopezes were seen. My question is basically where are the opening trends going as we go into the new decade?
With e4, a few that come to mind are the Rossolimo Sicilian, often to avoid Magnus' Sveshnikov, and the Najdorf never goes away. The Italian game, and the Ruy Lopez is another that never goes away (Magnus has 180 games as white alone with it).

With d4, the Catalan is still popular along with the various Queen's Gambit lines.

Obviously, very few things every go totally out of style unless they are totally busted, but to come up with the list, I used ChessBase to do "dossiers" on Carlsen, Caruana, Ding, and So; and then I looked at what they played the most, and ignore openings with lesser quantities of games. They seem to mostly play very traditional openings that take direct control of the center.

EDIT: First, I think that the Berlin was on a level all by itself due to Kramnik's successes, and because every top player plays 1...e5 a lot, and because the Ruy Lopez is so difficult to defend. I just finished watching "The Method in Chess" Videos literally just yesterday, and in one of the last two, GM Dorfman made a comment about how the Ruy is just "statically worse", and that black is mostly confined to the last three ranks, and white can choose to play on the kingside, center, or queenside, meaning that black always has to be that much more vigilant about white's intentions in any of the three areas. The Berlin solved that at the cost of a slightly inferior endgame, and thus, it solved it for A LOT of elite players. Therefore, it also got played a lot more often than most other opening trends.

I looked through my New in Chess Yearbooks, which are basically surveys of opening theory, and it mostly confirmed what I wrote above. Here is a list of players, who have played each of the following openings.

What I did to get this information was plug in the position I knew was popular from reading about chess over the last few years, and the Yearbooks, and then clicked on the Reference Database (Mega 2020) in ChessBase, and then sorted by ELO rating, and paged down to see what elite players played it. If they played it just once or twice, I did not include them. Nakamura was on the edge for a few of them, but I noted that.

Rossolimo with white: Carlsen, MLV, Aronian, Nakamura, Anand, Caruana, and Giri. I sorted the following search to bring up Carlsen's games as black to show how they are trying to avoid his Sveshnikov (far right in the picture), but he also has played it against Radjabov, Gelfand, and Dubov, among others.



Sveshnikov as black: Carlsen, Caruana, Grischuk, and Radjabov.

Najdorf as black: Carlsen, MLV, Ding, Grischuk, Anand, Giri, Grischuk, and again, Nakamura dabbles.

The Italian Game with white: Carlsen (19 games), Caruana, Ding, So, MLV, Giri, Anand, Karjakin, Nepo, Aronian, and even Nakamura has played it a few times.

The Ruy Lopez with white, and all have played it A LOT...more than any other opening I could find: Carlsen, Caruana, So, MLV, Anand, Topalov (even as recently as 2015), Anand, Giri, and Nakamura some. 

As you can see, while the top players may avoid one of the above, they are all very popular overall.