Kind of absurd that your OS (which is supposed to always be acting in your best interest) enforces these arbitrary carrier data limits -- it's objectively anti-user behavior and wouldn't exist if Android were truly FOSS (emphasis on "free").
This solution is great for permanently bootloader-locked phones (which is unfortunately, most phones).
Alternatively, if installing a custom OS is an option, most Android forks remove the tethering restrictions. I use and highly recommend GrapheneOS [1] if you have a supported phone (Pixels only as of now). DivestOS and LineageOS have much wider device support. ProtonAOSP and CalyxOS are other options for Pixels and a few others.
This solution is great for permanently bootloader-locked phones (which is unfortunately, most phones).
Alternatively, if installing a custom OS is an option, most Android forks remove the tethering restrictions. I use and highly recommend GrapheneOS [1] if you have a supported phone (Pixels only as of now). DivestOS and LineageOS have much wider device support. ProtonAOSP and CalyxOS are other options for Pixels and a few others.
[1] https://github.com/GrapheneOS/os-issue-tracker/issues/70