Isabella The drop in the skill level is partially due to the change of the game demographic.
Early games were primarily skill based or specifically made to be difficult so that the arcade machine could bleed the coins out of the players’ pockets. And mastering the video game mechanic was something you could go and brag at school about to others who play the same game. But times had changed.
The gamer demographic expanded and the games moving from arcades to primarily to console and PCs made it that the mastery of the game mechanic was not the only goal for the games. Also, making the game too hard now did not add to the income of the game, but rather added how long the gamer was playing. Sure there are still games like CS:GO, where the skill and knowledge of the mechanics is the key to success, but there are games like Wolf Among Us that have no need to master the game mechanic to enjoy. The difference is the goal of the game.
Some games are trying to be competitive like different variations of Battle Royale and MOBA. At the same time others are trying to tell a story/narrative, and having the complicated game mechanic will stop people from progressing through the story or narrative they want to experience. Hence the push of the easy modes and so on. In addition, with gamer medium age getting higher, there is also the time constraint on mastering the mechanic. The older gamers have other priorities than getting good at timing that roll to certain a frame or making sure they can time their hits to a certain frame. The result is the creation of the games that do not require high skill level but do have busy work added to keep people playing who want to play the game longer.
Finally the recent development, already discussed above, is addition of pointless grind, that originated from mobile gaming, to create incentive for people to pay to skip.