I actually don't think that games are 'worse' now, it's a combination of selective memories and a diversification of the gaming scene.

By selective memory I mean; we tend to remember old games as good simply because we only remember the good ones. I've played my fair share of bad-old-games, but I don't really think of them and so don't make mental comparisons to the more contemporary games.

And finally, when I say 'diversification of the gaming scene' I simply mean that there are so much more genres possible now that were not possible in the past. Those of us that grew up on older games are more likely to have played games with deep immersive stories, (Chrono Trigger anyone?) These storylines are not really that possible in the newer games that focus on PvP such as Call to Duty or other esports titles, sure some of these games do have a storyline, but nothing as deep.

This at least, is an explanation of why I tend to remember old games much more fondly. And also why I fell in love with Mass Effect, Dragonage, The Elder Scrolls etc etc.