Things that got ruined by popularity?

Airbnb. At the beginning it was a great experience with both renters and rentees exchanging little gifts, and personal handovers etc. Now most would agree it is better just to stay at a hotel.
 
Craft Beer

Used to be a bunch of nerds trying to create artisanal brews. Then a bunch of eejits who appreciate social media likes more than beer jumped on the bandwagon and now we have a bunch of liquid that tastes more like jolly ranchers
 
Deadpool.

Used to be a complex character with deeper moments and a lot of heart. The Internet picked him up and now he's all just lolmemes. He lost what made him special.
 
Produce. The "organic" fanatics popularized a buzzword all by themselves and companies immediately slapped the "organic" label on everything and marked up the price. For a while I could still buy non-organic produce but slowly they just got rid of it and now only sell overpriced "organic" produce.
 
for me, it's social media. it started as a fun way to connect with friends, but now it feels oversaturated with ads and unrealistic expectations. what used to be a space for genuine connection has become more about likes and followers than meaningful interactions.