"My understanding is they have to be easily accessible."

Never so "easily" in any code.

It is NOT an emergency shutoff, that is at the meter.

It IS a maintenance shutoff, so it can take some work to gain access.

The most common rule enforced is that you cannot destroy anything accessing the valve, but it can be behind things (like the stove, behind a drawer that musty be removed, etc.).

Often you have to remove a bottom drawer on a gas stove to get to the valve.

One big rules is it must be on the same floor of the building.
No putting it in the basement ceiling under the stove.

Ball valves with a handle seem to have taken over from the older square style gas valves that required a wrench.
Many ball valves are marked as WOG (water, Oil, Gas).