It didn't fell off, just became oversaturated due to the rate they release TVS/Movies. Back then, it's easier to play catch up if you missed a couple of movies. Now, if you missed something, it becomes daunting because it feels like a lot. It's also hard to get hyped up. The feeling of actually marking down the release date of the movies back then is so different than right now. I personally think speculations + theories are part of what makes MCU exciting. Today, you have no time to get hyped because after one series ends, another will start the next week so there's no point.