Higher beat quartz watches do exist, like Bulova's Precisionist watches (which I believe do beat 16 times per second like you mention).
My understanding is that they are not more common because moving the hands more frequently like this uses battery a lot faster, so the watches either need to be bigger for more battery or require more frequent battery changes.
Yes but if you need 1500 points at minimum before you can cash out, that means you aren't seeing any cash back until you've spent $300 at Microsoft. The payout might be bigger, but you have to wait a lot longer to get it.
If that's worth it for you, that's great! But if I'm spend $60 at Microsoft a few times a year, I might rather just have $1.20 next month that I can spend on many things than $3.00 in two years that I can only spend at Microsoft.
Wikipedia does not appear to be in any danger of running out of money: https://www.dailydot.com/debug/wikipedia-endownemnt-fundraising/
I think it's a good thing they have an endowment to give the site more financial security, but... how big does it need to be before they stop the begging advertisements? They've already far outpaced the goal they set in 2016.