How many examples of games simply not working properly (Assassin's Creed Unity, Mass Effect Andromeda, Arkham Knight, Battlefield 4, ect) or release without any substantial content until later release (No Man's Sky, Sea Of Thieves, Evolve, Anthem, Fallout 76, ect). Not to mention the cost of entry is pretty substantial in modern times being games now cost ~$90 if you want all the content, if not more. Multiple special editions are becoming a new norm, so you can't even go buy a special edition and feel like you got everything, because most the time you don't (such as BOTW collectors edition has different things than Master's Edition). How many games can you on day 1 sit down and play all the content and it actually work. Very, very few.
Yeah, I'm pretty sure there is a pretty big case for games not being as good as they used to be.
When games are broken now, they can be fixed. Maybe you weren't gaming in the 80s and 90s But, I was. Back then, sometimes you'd get literally stuck in a game, with not choice but to restart. That also meant huge lost progress, because of the relatively save options. Sometimes, you'd get stuck in a glitch in the final level, and have to start the whole thing over. Thankfully, those days are long gone. Games now either work, or they're fixed.
As for cost of entry, there's no comparison. When adjusting for inflation, games are cheaper than they've ever been. They're also much, much bigger, on average.
So, sure, there have been some changes that one could argue are bad. But, they're have been a whole bunch that are objectively good. I simply don't see any case to be made for games being worse now than they were - let's say 25 years ago - except totally subjective personal opinions.