I was able to coax one to the surface and finally kill it after getting high above it and raining down infinite flaming arrows, but hand-to-hand I'd be dead meat (again).
I've built a covered entryway for the stairway down, with some beds & chests to keep your preciousness safe if you dare venture below.
Bonus neato 1.19 stuff: if you kill a mob (any mob) near enough to the enclosure you will grow sculk blocks/veins around the area that they die.