This is just not true. There are tons of good games that don’t get anywhere near the attention and sales that they would have during the early 2010s. In fact the only way this is true is if your definition of “good game” is “commercially successful game”.

Easy examples to point out are things like Tumbleseed: https://store.steampowered.com/app/457890/TumbleSeed/ or Mushroom 11: https://store.steampowered.com/app/243160/Mushroom_11/

And those are both 5 years old and things have only gotten harder since then!