Curious. Why did someone think it necessary to do sharkey and iceshrimp. What is wrong with Misskey?

I'm curious about people's thoughts around Misskey and its forked projects.
1. Why is Misskey so popular in Asia, but not used much in the west? Why do you think the preferences are so different between the regions?
2. What is wrong with Misskey that some people are willing to invest their time and money on separate forks (IceShrimp, Sharkey). What's the difference between the forks and the originals?
3. Does anyone have experience running any of these? Do they have any downsides like, for example, a database that grows unreasonably fast or that requires too many resources?