I know I become hyper aware of any small black specks in my peripheral vision since they resemble spiders that could have posed a threat to our ancestors so we evolved these heightened senses to avoid them.
And in nature you do not really have much big objects that could fall on you if you climb them.
Maybe a large boulder loose ... but they are very rare in my experience. So I guess it makes sense we are not prepared for it. What is much more likely, a loose rock which breakes off at climbing .. we are prepared for. Instinct reflexes are pretty fast in that case, I noticed ..
I would hope the ability to sense loss of balance equilibrium would innately result in having the strong urge to bail from that activity to sturdier ground, given you knew you could safely land on the ground without a worse outcome.
A tipping cabinet takes much longer to fall unlike a rock dislodging when you are climbing the side of a cliff in nature. Maybe it is simply a blind spot in our evolution like you suggest, evolution never optimized us for this edge case scenario not experienced in the wild.
1. https://www.mayoclinic.org/diseases-conditions/dizziness/mul...
This very thing happened to me decades ago: I walked into parents' bedroom to find my fearless younger brother, ignoring my yells, climbing up the handles on the front of my father's dresser. I yelled for my parents but I couldn't stop him fast enough. As the dresser began to tip I got between him and it and pushed upward, both removing him from the dresser and tipping it back to rest.
I was truly shaken and astonished that this child might have killed himself, since I knew that the top drawer was filled with my father's most valuable (and heaviest) WWII memorabilia and that the entire dresser, about 5 feet tall, was hardwood with decorative protrusions on the front.