Help me understand the USDT vs USDC comparison.

I already read about USDC transparency and audit problems with USDT, but I'm still not sure if there are any real risks in USDT, especially for mid-term holding. Sorry if it's a dumb question, but I'm really confused now.

I'm considering this only for usage in crypto-landing and short-term holds in wallets, so trading volume is not really a point for me here. Also, I assume that any real problem with Tether will have a global effect. Also, is the diversification inside stablecoin providers the case?