I use Objective-C when using interfaces that require lots of C-style parameters. In particular Metal requires unsafe pointers to vertex and fragment data and I

I use Objective-C when using interfaces that require lots of C-style parameters. In particular Metal requires unsafe pointers to vertex and fragment data and I find the contortions you have to use to get Swift to send such data to Metal to be too much work. It’s just more straightforward in Objective-C. It can be done in Swift, but it ain’t pretty. (Or at least, it wasn’t the last time I tried, which admittedly was about a year ago. Maybe it’s better now?)