Just recently I was doing a presentation with my MacBook Air 2013 laptop. A worker not paying attention walked by and knocked the power cord and it ripped out of the laptop. If I did not have a MagSafe power adapter, but a now usb-c power adapter like the current MacBook Air, the laptop would have flown to the floor and probably broke.
But..all the worker did was pick up the MagSafe power cord off the floor and plug it back into the laptop and say, “Oh, I am sorry..”. The laptop did not move when the cord was yanked off. Again, the force of the yank would have sent the laptop flying…
so plus one for MagSafe, but it can be designed to be used with a usb-c port and just attach off. I have seen third party MagSafe adapters for usb-c (don’t have one), so it should be easily done.
My wife was careless on a lightening cable hooked up to my iPad mini 5 and it wound up breaking off a piece of the connector inside the iPad. She was able to get the piece out. The iPad mini is in a very sturdy cases so it did not suffer any damage but a laptop would have.
I am surprised that there aren't really good MagSafe-like solutions with USB-C charging these days. Apple really seem to have gotten it right with MagSafe I and MagSafe II. It's saved my 2014 and 2015 MacBook Pros a few times.
Other good reasons (besides people tripping or being careless) are pets and kids.