Yup... I agree with you. Whenever I need to make sure that my investment doesn't go down in value, I just convert them to USD. Tether is going through a lot of problems now. I will not trust that currency until they publish their audit findings.
Well, do you really convert it into "USD" or, for example, into "BitstampUSD"?Exchange "USD" wallets are equally risky than Tether and other centralized "stablecoins". You could obviously try to use the most "established" ones (like Bitstamp) but I think everybody here remembers an exchange called oficially "Magic The Gathering Online eXchange"
(There is actually an exception: There are a few European exchanges, like Paymium, that store their USD funds in a wallet of a partnering "bank-like" payment processor. In this case, if the exchange ceased to operate, in theory the State "backs" the losses and will return amounts below 100000 EUR as part of the Deposit Insurance.)