The short version is that to actually use 160MHz you needs to use DFS channels. And depending on if other networks in your area are already using them you might benefit from manually picking the channel.
To manually find a better channel you could install WiFiAnalyzer on your Pixel and then change the channel (e.g. 100, 104, 108, 116, 120, 124) until you find one that increases your signal (e.g. from -55dBm to -48dBm).
However, you might want to try using AC instead of AX or 80MHz instead of 160MHz because the mt76 WiFi driver that the router uses has been known to have issues with some Apple devices.
https://forum.openwrt.org/t/802-11ax-worse-than-802-11ac-with-mt76-driver/126466/103
https://forum.openwrt.org/t/802-11ax-worse-than-802-11ac-with-mt76-driver/126466/180
https://forum.openwrt.org/t/802-11ax-worse-than-802-11ac-with-mt76-driver/126466/533
https://github.com/openwrt/mt76/pull/768
https://github.com/openwrt/mt76/issues/748
https://github.com/openwrt/mt76/commit/f9ca70d6367a16fecd80b93fec60fb0d4e3b9fd0
I’d assume GL.iNet had WiFi fully working at it’s expected speed at one point during development, but over time changes to the driver, hostapd and EEPROM have introduced bugs that cause slowdowns.