My understanding/experience is that Titanium is so strong, you don't really need to consider it bending or breaking.
There's a common anecdote/trope that you'll be able to weld a steel frame back together. I would say, no. If you literally snap your steel frame, you're hitchhiking back to civilization because it's going to be difficult to impossible to get a fully functional bike out of a hack weld job, not withstanding the difficulty of finding a welding torch in the middle of South America/Africa/Middle East.
I bent the steering tube on a steel fork in Montreal. Montreal has a bike shop every 300 feet. I visited four, and all four said it was unfixable. The final stop called a framebuilder, and the framebuilder said the fork just couldn't be bent back into place.
That might be some indication that a steel frame, while resilient and reparable (I have bent steel drop-outs back twice), is not a perfect medium for repairs.
So, Titanium is just so burly and so overly strong for cycling that, so long as you're not hit by a car, it won't see damage. if I were to do an "around the world" style bike tour, I would take a titanium frame.
There's really only one reason to choose steel over titanium, and that's cost. If cost ceases to be a factor, go titanium.