are there cards that accept BTC directly instead of stablecoins?

I hold BTC and don't want to swap to USDT every time I need to spend.

Every card wants stablecoins. Are there any that accept BTC directly with instant swap at load time?

You're asking the issuer to take BTC volatility risk. That's why they don't do it.

Asset	Volatility (30d)
BTC	±18%
USDT	±0.01%
USDC	±0.01%

If you load $500 in BTC and it drops 10% before you spend it, the issuer is short $50. They're not in the speculation business.

swap it yourself

Then swap it yourself before loading. You're asking the issuer to add complexity so you don't have to manage your own portfolio.