This is how stupid companies are. Those 4% may not be a viable demographic of itself but by not supporting that 4% you explicitly tell them to pirate.
4% of revenue at this scale, minus server costs, is an enormous amount of profit. Supporting one extra browser/OS combo should take less than one dev.
What's beyond ridiculous is that I get HBO Max with my internet but I can't use it. Great...
The only sad thing here is that most people in the US don't have the possibility of choosing a different ISP/Cable provider because they are all monopolies.