I've been using tether for 2 years now and I feel tether is one of the best stable coins out there. There have been concerns about tether in the past. But remember tether is a mainstream stablecoin and 3rd in the market cap after Bitcoin and Ethereum. Therefore do not worry about its downfall, its very unlikely to happen. But you can always split up your money in USDC and USDT to make sure your funds are safe.