Bittrex is one of the most popular exchanges today. It is a platform for the exchange of cryptocurrencies. It is good for investing in cryptocurrencies with a large amount. Despite the accusations, for me it is not a scam and there is no need to fear fraud with them. I do recommend maximizing care regarding the password, do not give it to anyone, make it unique and exclusively yours, etc., and configure the account to use the two-step authentication system.
Most of the opinions are good, although there have been complaints due to the slow processes in the verification time and the responses from the support team. However, things are normalizing and I'm sure it will improve.