As as a chess player I am now past my sell by date, nolonger at my best now at 68 I nolonger compete at high levels in over the board chess, I did 30 years ago hit a 1800 rating o.t.b but now only play online friendly encounters! The one element you need to be reasonably successful at chess is to have a good tactical game, being able to calculate at minimum least 4 _6 candidate moves ahead, openings and Endings can always be learned but without a good tactical game and able to decide which candidate moves ( the good from the bad) you will always struggle in chess Capablanca called it the fundamentals of chess!!
I am on GM-Level and could beat Carlsen in a match. And I say calculation is not that important. In 99% of the cases experience and intuition r much stronger. And of course pattern recognition is also much more powerful. If u just know. If u have to calculate u can make mistakes.