I have used Brave on average ~4 hours a day for the past 2-3 months, and yet have received almost no ads and very little revenue (~0.5BAT over that time). I have always had fairly low rewards, and although I love the browser I seem to repeatedly have this issue over the last year or so where I just won’t receive ads.
I have my ads set to 10/hour, reside in the UK and my version of Brave is fully up to date (v1.36.109). See below some screenshots for verification. I’ve verified my wallet countless times.