When you spend hours doing cross browser capability checks on your PC workstation at work and your web app looks like trash on Safari on your Mac at home.

I'm opposite; I code on a Mac and have to remember to test in IE on PC, only to find out it looks like shit. (Safari is just as bad though!)

Imagine the total hours and cost spent by all developers on cross browser issues.

I remember back in the day when people touted web development as being the solution for cross-platform compatibility. "You build it once and it will run the same in every computer. Much better than having to write one program for each OS." Or "just use Java."

I'm glad people don't do that anymore. They just use React and it will work perfectly in all platforms.

Oh wait...