This is where it gets weird. If an Uber driver's idle time between calls is built into their pay, then a driver could use that time to work a second job. Essentially double-dipping.
I'm not against this. It just makes for weird comparisons.
It's not double dipping, because there is no compensation for idle time, and you can only take one passenger from one app at a time. So if Uber and Lyft both pay $30/hr for actual driving time, then go ahead and have both apps open. It will increase your paid hours per total hours spent, but it could never create a situation where both companies are paying you for the same exact time spent.
I'm not against this. It just makes for weird comparisons.