I like the minimalist featureset. I end up making the sketch, not shaving the yak. Yes a rectangle makes a perfectly good text input, and also a mobile phone screen. It's a versatile shape!

You can select the label and the arrow and press control+G to create a group.

You can also do the opposite, pin the arrow to the label so that if the label moves the arrow follows: double click the arrow to see the path points, select an end point and move it on top of the label until you see the bounding box of the label.

If you know in advance that you're not going to need a more powerful, more complicated/expensive/... tool, then it's okay and even recommended to use the "lesser" tool. If I need to screw in a few screws, am I better off buying a small screwdriver or a professional 18V screwdriver/drill combo with 24 add-ons? Who knows, it depends on my projects and my skills, but it's entirely possible that buying the $5 screwdriver is the appropriate thing to do.