The AMD RX 6600 XT wins in 7 out of 14 comparable specs, with 2 ties. Its biggest advantage is Boost Clock (50% better).
RTX 3070 wins in 5 specs (Shader Units: 188% better).
Recommendation
Choose RX 6600 XT if you want the best overall performance — especially boost clock.
Choose RTX 3070 if shader units matters more to you.
