is that true? Why are there so many IEO projects now SCAM ?,
it's terrible to see that altcoin prices are now sinking

Buddy, IEO Projects are not scam.
Exchanges are SCAM!
Do you have any evidence about that whether are IEO project is not a scam, If you are blaming about the exchange then you shouldn't on those exchanges? We have seen many IEO's who have lost their value in the market after the conclusion of their crowd sales. I am one of them who faced losing situation when I participated in IEO.
Talking about the problem I personally can not give any answers because I do not have any evidence,
certainly this is a pretty complicated thing whether the IEO project is a scam or a scam exchange
read all details here -
https://www.reddit.com/r/wantmarketplaces/comments/dcflsk/scam_zbtc_exchange_zbtcexcom_and_abex_abexbcom/Life is simple. If they sold 500M Tokens, where is the money. Any Wallet where you can see $3.2 Million USDT?
If you still do not believe it, go ahead and make a account with them and deposit your hard earned crypto.