M1 Macbook Air (M1 MBA) 802.11ax/WiFi 6 is slow

Keep in mind that 802.11ax / Wifi6 had a particular focus on performing "well" in noisy environments, supporting much higher density in a given space due to the use of more narrow channels, and higher client density on a given access point, which is why it's being pushed in enterprise deployments. Apple likes it for that reason, because they're all about "experience" where lack of errors, disconnects, etc. take precedence over raw throughput that many people won't notice. The same issues that often made 2.4ghz undesirable still cause problems with wifi6 because now the computer can use both frequencies simultaneously, where the 2.4ghz side can still become a problem that affects overall throughput and latency by way of the same wasted time with lost packets and retransmits.

For personal use in a noisy environment, especially apartments / condos, but even single family homes depending on device counts and similar noise generators, you may find disabling the 2.4ghz side, or going back to 802.11ac, produces a better throughput and experience if you are needing it. I use a lot of transfers to/from local network storage so I saw an appreciable difference in forced 5ghz, which stays pretty reliably connected at 1300mbps, even though I'm getting less than the protocol is capable of in a lab.