Send current location in Messages app running iOS 12
Tap recipient’s name > info button > Send My Current Location (or Share…)

Sure, It's just two taps away. But it's not visible, so you wouldn't know it by looking.

Tap the name under the icon for your contact in details. (this tap target it pretty small, so you might miss it first time you try)

The panel expands to display audio, FaceTime, and info buttons. Tap the info button to display a panel with several items. One of this items is the option to send current location, either snapshot or ongoing.



Then tap, Send My Current Location (this one is thankfully easy to tap)