I dont thins so, but there is nothing 100%. Tether (USDT) is the third biggest cryptocurrency by market capitalization. It's also the biggest stablecoin on the market. But its popularity doesn't necessarily make it a safe investment.
popularity will clearly determine people to make USDT still used as one for trading. because as a stable coin that is still very reliable today. like you said USDT market capitalization is also very good is an acknowledgment, because indeed all use USDT for transactions more efficiently so that prices do not change according to their wishes. Therefore, it is not surprising that it is often used as the most secure transaction tool to date.
When it comes to being safe or not, you can be sure that everything in crypto can change at any time, but realistically it's not that easy to disappear right away.