Can someone please tell me why this good altcoins are getting delisted from bitone exchange?is there any other reasons why coins always get delisted while they have good volume?

I'm confused because quantstamp and status aint bad at all,they have good marketcap and good volumes
After a while of searching, I found BigOne users mostly from China. And maybe their users don't trade these altcoin much. So they decided to delist them
That will definitely be the reason behind the delisting of the mentioned coins because every crypto exchanges site has their rules and regulation about coin delisting. Besides, some of the coins are traded on some top exchange site but the delisting news has already affected the coins price in the market.