With 5.10.16, along with a firmware update (kernel-firmware-iwlwifi-20210208-1.1), I don't see issues anymore. I am connected on 5Ghz (the issue before only appeared on this band), I have removed all iwlwifi options from modprobe and I have not seen any errors in a while, where before I'd suffer them every one or two minutes. The last kernel release has indeed included fixes to iwlwifi: https://lwn.net/Articles/846116/