Is there a way to share a tight staircase/steps with pedestrians? One of my destinations in the city has a peculiar access route - I need to descend a very narrow set of steps, a staircase, which has barely enough space to let two pedestrians pass.
I'd estimate its width as 150 cm. It's not as steep as staircases which we use to access higher floors in buildings - its inclination angle is maybe 50%. It's an outdoor set of steps, which connects two streets.
An alternative route exists, but it is longer and is less fun for me.
I have never tried descending there with my MTB, because if a pedestrian tries to ascend the staircase while I am going down, he will probably get scared.
Trying to think from the pedestrian's perspective:

The guy on the MTB doesn't look he is going to stop, and there is absolutely not enough space for him to pass by! So the only way to prevent a crash is to [do something desperate and stupid]!

Objectively, this is nonsense, because I have no problem stopping, and legally and ethically I am obliged to do so. But subjectively, the situation can be very intimidating. I guess that shouting something like &quot;Don't worry, I'll let you pass&quot; will only make it worse.
Can I prevent this situation?
I've had to commute routes where I need to use a narrow staircase to go up and down a pedestrian bridge over a highway.
For starters, any place where you have to share narrow space with pedestrian, the polite way to do so is to dismount.
I shoulder the bike or walk it. The bike always goes to the far side ( If there is  a fence or wall, the bike goes towards that fence or wall or guard rail. ) so there is less chance to hit another person with a protruding pedal or handlebar.
While going down stairs, I sometimes roll the bike on its rear wheel, holding the handlebar up and using the brake to control it. That way my combined bike+rider width is minimal and that will let another pedestrian pass, even if they are also carrying a bulky load.
Consider that even if you believe to have good control over the bike, there might be something out of your sight that may cause you to temporarily lose control or may need you to perform an unexpected maneuver (e.g. a piece of garbage you ride over and it makes you lose traction). If that happens at the wrong time, you may hit another staircase user. Better to play it safe and dismount.
I've ridden in a city where there are shared bridges (pedestrian/alternative transport) but it is mandatory to get off your bike, skateboard, or whatever you are riding. You mount again on the other side where there is a wider and dedicated cycle path and a walking lane.