I saw in some comments some people dissapointed or saying poloniex is scam, what do you think?
Just to add to what the first two posters said above. I did not want to rely on trustpilot reviews alone, so I took a look at Poloniex's reddit page and there are many dissatisfied customers complaining of their services. The scam accusations against them are overwhelming and not looking good.
Aside Poloniex, there are many other reputable CEXs you can settle for, if Binance, Kucoin or OKX are allowed in your jurisdiction then I'd suggest you use either of them.