The algorithm tests are there to have an excuse to discriminate on other criteria. If you can mask your racial/age/gender reason for not hiring as a FAANG with "oh, we didn't like their algorithm solution" you always have an out.
I feel like this "only" is erroneous. While FAANG do have solid diversity policies in place to assume they're the only companies capable diversity in their hiring practices is offensive to everyone else.
HN has the best thread for discussing the caste baste discrimination that happens among Indian tech workers in the USA. It turns out that being white still gives you a lot of privilege, even in tye FAANGs.