How did most of the famous servers die?

Most likely the server becoming too expensive for the owner to run, or maybe the owners just get bored

Also , Hypixel is more intresting than most server as their dev keep updating new content .

People just stopped playing the game modes. TBH i think the servers didnt evolve quick enough

Hypixel contasntly released new updated content while the others slacked off and so hypixel became the main server

I think its just that they got to popular and less people felt connected so people start leaving them.

They died because most people stopped playing minecraft and started playing something else. Also, a lot of new servers were born at that time and they had a lot more features than the more popular ones.

Compare hypixel to mineplex. Hypixel is constantly updating, getting their users engaged, and brings new and modern ideas to the table. Mineplex has just stayed the same. Personally, mineplex just feels old. Lots of hackers plus many newbies playing on mineplex is also another turnoff for me.

i think the owners dont have more pay atention to players and the server will probably die

Cheaters are definitely the go-to reason nowadays. Either that, or the games are getting dull for people. Servers aren't coming out with new material

More new games are introducing making Minecraft has less people to play on .
Also , Hypixel is more intresting than most server as their dev keep updating new content . Mineplex died from staying the same. Tbh I felt like it was a messy setup and wasn't that enjoyable compared to Hypixel