You can use BAT tokens to pay for content creators you like (youtubers, article writers, etc.)
My question is, what can content creators do with BAT tokens other than exchanging them for FIAT/ BTC / ETH ?
Actually that part is optional. As pointless as it may sound, you can use Brave browser without bothering with BAT. Tho its just another Chromium browser.
You CAN give BAT to content creators, and handle your tokens with it. The first promise has not been fulfilled, that you would be paid for watching ads. In fact the plan was to replace ads with their own... That was even before they made their own token, i think even Bitcoin was mentioned back then.
But at this point they won't give you BAT for watching ads, you can only give BAT for watching content. And there is some referral program which is why you see sometimes people spamming Brave around.
Oh yes, you can block ads and not give any BATs too, like any other chromium browser it can use the same addons, such as ublock origin, etc.