"Any good knife shouldn't break", the caveat being that you have a bit of knife understanding and don't push it to its limit. Some knives do seem on the brittle side and now we have "battening" being in vogue everyone expects knives to baton logs. Frankly to get a fire going with dry inner wood requires at most split sticks. If you only have a SAK on you then thats what you can but use, the rest is brain power.
The CS Bushman is made of a spring steel as are so many machetes. They may not keep an edge for long but are hard to break. There are some tough knives that will bend before breaking too, but again their edges don't last long. Or built thick so they can't break with a harder steel. Many are hopeless at cutting and loose too much utility to outright strength. All this thickness and weight isn't necessary or desirable. I think we have been conned, as we are being sold and have bought into some pretty inefficient tools. The sorry story further exacerbated by some over enthusiastic knife reviewers that really don't use a knife for work other than a play in the woods. (I'm one too, but getting less trendy).
One of my pet hate knives is the British MOD survival knife. It may be difficult to break but its a thug of a knife and a brick. Not a good cutter, rubbish grind and too short as a chipper. Its crap.
I respect Busse knives for what they are. Sadly I think they are too heavy and overbuilt to carry far for their size.
Most high cost blades are just too expensive and rare to find in remote places where their qualities might find use.
Note the amount of re-profiling done on many of the usual survival knife suspects. Work to make the factory offering actual do an adequate job.
Another pet hate knife are thick bladed bushcraft knives.
And any knife that is sold to chop more than a sapling.
Survival is using whatever is at hand. Train with great and poor equipment, as then you won't be at a loss that you don't have that gukki kit. Survival is not glamping.
When I do have a choice then I'll have something that good at its job. There are too many vid on Y tube of people chopping through a log with a small knife. That is far too much energy being used and no survival test. It might test the knife a bit, but most are pretty terrible at it all; well they are on the ones I've watched. So many are straight forward poor at being a Knife!
Yes, there are some nice knives made. Knives that are knives and not sharpened slabs, or just so overbuilt they don't cut well. The world was tamed with axes, saws, and little sharp kitchen knives. My preference is for efficient cutting machines made well that have just enough weigh to do the job. Its all a bit like too much scope on top of a rifle to go hunting with. A 21/2lbs sniper scope on a 12lbs plus rifle that is rarely going to ever shoots beyond 200m.