You can definitely bike if that's your thing, I mean it's 35C right now, but there are a lot of times when it's 40-45C. Or occasionally 50C.
This could theoretically be good for someone who works from home primarily, but you really do need access to a car to get around Phoenix in general. Some day you're going to want to visit, say, the Renaissance Faire and biking from Tempe to Apache Junction is unlikely to be an attractive option for most people. And I pity any Uber drivers that get contracted to help get someone through the traffic jam for that.
There are a decent amount of bike lanes and whatnot, but the city was optimized for cars, which is why all the self-driving tests are there and you can see a Waymo every other day or so, including that new smaller car.
The light rail is great if you want to go to downtown Phoenix or the ball park and maybe for ASU, but a bit less attractive for many other destinations. Meikong Plaza and H-Mart on Dobson aren't very far from the light rail, but walking ~1 mile in 45C weather with groceries only works for the younger and healthier folks. Asiana or Fujiya are probably non-starters for someone using the light rail, being 2-3 miles away. Don't get me wrong, you can take your bike onto the light rail (or bus) and get there, but it's a significant effort and if it's one of those few days that hits 50C, most people's willpower will give out.
I'm surprised they don't compromise a bit and have a handful of community cars that are shared by some agreement. Then again, I suppose that Uber/Waymo can take over there. It honestly looks pretty cool, but we tend to use the cars a lot and outdoor stuff is only attractive between October and May or so.