Thanks to DFS restrictions in the US, there are effectively only two 80 MHz channels that can reliably be used in the 5GHz band.

2.4GHz only has three non-overlapping 20MHz channels, and those can only do ~286 Mbps throughput in the best case when using 802.11ax.

The 6GHz band is finally allowing 14 non-overlapping 80 MHz channels and 7 160MHz channels, without any DFS restrictions (though some channels are lower-power/indoors only).