Babysitters on their phones

We find our sitters through a popular sitters app since we're new to our state. We've had some really awesome sitters this past year. Maybe recently we've had a bad run of luck or maybe my expectations are off? Please set me straight. My 12yo and 6yo sons have asked us not to use 3 different sitters in recent months because "they sit on the couch on their phone the whole time." My husband says that they're really just there to keep them safe or call 911 if needed, but I suppose I was hoping they'd engage with the kids more? We pay the sitters their asking rate which is typically $25-$30/hr. I do make it clear that I would prefer the kids play outside or find activities to do inside from our homeschooling/ game/ arts & crafts room. But maybe it really is just hiring an adult to be present in case something bad happens? I guess I'm currently a bit peeved right now because we hired a 36yo mom only for my kids to complain about her and she was pretty upset when we got home because she couldn't figure out how to use our regular oven OR our toaster oven (it was unplugged) to heat up the dinner she brought for herself. My 12yo asked us not to have her come again.