We’ve been able to do this for years, largely for free (ignoring the costs of the computer and devices), but I’m not sure as many people know about it as they should.
TL;DR: XCode comes with a “Simulator” program you can pop open to test in virtual iOS devices. If you then open Safari’s Develop/Debug menu, you can use its DevTools to inspect right there — also true if you plug in your real iOS device.