I'm currently getting 2 Web Stories offers repeatable around 3-4 times a day and a Tobacco Prevention video offer that lets me do it 10 times per day, under SupersonicAds Video offers. A few weeks ago, I did start running into an issue where the offers would just load as black boxes and be impossible to complete. However, if this is the issue, you can still do them by repeatedly clicking the offer while the page is loading.
Open the SupersonicAds video offers in a new tab and then press f5 while repeatedly clicking the offer you want to do; it should load properly when you do that. (Note that available offers differ for each person.)
I've also had some success with the Peanutlabs & Persona.ly surveys; they generally don't ask for any personal information more identifiable than zip code & birthday, and you can just fudge the final digit of those without affecting the survey. But I usually had to do over a dozen surveys before I found one with a matching target audience, so this is only for when you have lots of free time.