If you can wait, I'd wait. If you can't, you can't. This one is probably a good buy.
WiFi 6 is improved all around compared to 5, not just bandwidth as mentioned here over and over. (including on OP's point 8 and potentially 9)
The major benefit(s) isn't really about "speed"; It'll work a lot better in crowded wifi areas (like condos), it'll handle higher number of connections better (thanks to OFMDA) and also should improve battery life of devices (which won't apply much now as very few of them are on wifi6) - and also WPA3 is a big thing security wise.
But then again, if you can wait, might try to wait for WiFi6E, and that's not like "at this pace I'm waiting forever" kind of thing. Considering the from n(4) to ac(5) to ax(5) we had roughly 5-6 years apart, 6E should be arriving by the end of this year, and getting into the shelves by next year-ish.
huuuu! (¬'-')¬ C-('-'Q) straight!