Following on from what Suziblue said, I would be very surprised if those independents advertising at £300+ p//h are seeing 4-5 guys a day. 2-3 per day is more likely, if that, and many don't work every day either.
FWIW, my one hour fee is higher than this as I have never wanted to see 4-5 days, 5 days a week. I don't use any of the sites you've mentioned apart from AW. AW brings in the fewest clients and always the most problematic ones, unfortunately.
Also, it is worth considering that many men still aren't visiting escorts at the moment.I expect it is more that rather than anything you're doing/not doing. Let life open up again and if things still haven't picked up my late summer, then it is time to makeover your profiles and website.