Not great by modern standards... The standard ESP32 supports 802.11n, but only 2.4 GHz (not 5). So theoretical rates maybe up to 40-50 Mbps. In tests that I have seen people do on ESP32 they have reported practical speeds of 5-10 Mbps. Which is basically just in the typical range for Full HD video.

The ESP32-C6 has WiFi 6 support and 5 GHz, so theoretically that can be order of magnitude faster. But it might have completely different hardware and require separate reverse engineering. And practical speeds will still be limited compared to dedicated WiFi hardware.