The game hasn't changed. The "conventional wisdom" on how to play has both evolved and split into different camps. It used to be pretty much 80% - 90% played a TAG starting hand set and went passive post flop without a made hand.
Now you have that group, the LAG style see a lot of starting hands and exploit post flop when the old camp goes passive.
Then we have a new "GTO" camp coming in and playing more of the
odds game versus how the actual cards and hand is developing along with the old 10% of play anything and bet in position to apply max pressure crowd.
This has made it harder to win fast at cash but a slow and steady return is still possible. MTT's are really the same survive early and play smart late is what it takes and just grin and bear the variance losses.