There is no universal solution to this. Some vendors support fwupd (LVFS) on some hardware (Dell, Lenovo), some allow to update via a file on a USB stick (Asus).
Unless it is a system from Linux first company (Tuxedo, StarLabs, System76, Slimbook) expect to manually check what the specific model you are looking at supports.
system from Linux first company (Tuxedo, StarLabs, System76, Slimbook)
Indeed that's IMHO the solution, namely prioritizing ecosystem that genuinely see Linux as something valuable, with an addressable market, rather than a cost linked to annoying users.