These two methods of savings are good , it only depends on what the individual want.when you safe in USDT , you safe against naira devaluation, your money will remain intact but will not grow in value, but when you safe in bitcoin, you safe against naira devaluation and your savings is bound to grow with time.For those saving for long time, i recommend saving in bitcoin because it gives room for financial growth, but for those saving for short period of time, i recommend saving in USDT to avoid fluctuation of your savings.
You explained it well. The main difference really comes down to time. USDT is fine for short-term safety, while Bitcoin is better for long-term growth and protection. Knowing your goal before saving is what makes the choice clearer.