Reddit changed for the worse when they shifted from community focus to business focussed. There are so many ways that changed the website and everyone will tell you the same. The redesign was the last straw that got me to leave the website. These days the website is packed with adverts, incredibly slow (it takes about 15 seconds to load on mobile) and its packed with an incredible amount of tracking.
The content quality has gone down as well but I can't ever say reddit was known for high quality content.
Also the fact it has so many users has caused its decline. Reddit today has so many obvious shill/advert posts.
>incredibly slow (it takes about 15 seconds to load on mobile) //
I think that is to ensure that when they tell you "it's faster to use via our app" that they're telling the truth; certainly when the 3 "use app" buttons per mobile view came along mobile appeared to get slower (the change also including cunning "continue" confusion to make people think they're continuing to use the website but they're really "continuing to nothing and instead changing your mind and installing our app").