I was speaking mainly for cutting purposes, so does the flexibility help with cutting? I'm basically wondering if a machete offers a cutting advantage over a similarly sized knife of the same weight with a full flat grind. IME machetes bend rather than flex, and flexibility depends more on cross section than temper, though both are important. The machetes I've used were generally in the range of 1/16" to 3/32" thick, and quite soft.
What kind of machete was used in the video? Looks to be about 18" long overall and ~2 inches wide.
Hey me2... The knife used in the vid is a Lainhart Machete, roughly similar to the RTAK. It is 15-1/2" OAL, with a 10" blade, 2" wide, 3/16" thk with no distal taper. Flat bevel, about 1/2" wide, convex edge. Blade is ATS-34 (only Stainless machete I own), hardness 57-58 Rc (most machetes are in the mid 40's).
The knife was used right out of the box (VERY sharp, I was impressed! :thumbup

Some have complained about the weight of this knife (< 600g, I believe). I think its perfectly weighted for this work. It feels VERY solid in hand and has excellent balance. Blade has a slight (2-3 degs) rake, that really helps with Big draw cuts. Compared to the other knives I own, which are mostly full convex ground, the flat bevel on this one allows you to easily control the direction the chips fly, @ least with this type of cutting.
For reference, we usually cut coconuts with my old man's 14" Martindale machete. He cut it down (before I was born.... and I'm 34

) to a 13" clip point. Still going strong. Completely different handling characteristics to the other knives, more "whippy" (only 3/32" thk @ handle). It is like swinging a light, sharp, razor blade. It makes the most beautiful "ring" when used.... sigh... like when knives / machetes / really ANY manufactured item was made right and made to last
Honestly.... I prefer cutting with the other knives like that Lainhart, RTAK, and ethno knives like the natas, bolos, and parangs. Their thicker blades, heavier weight, and convex grinds let them get thru things the machetes have a MUCH harder time with.
Hope this helps!