First, the strength of knots depends a good bit on the SPECIFIC rope type, so let's just agree that all of the data is probably correct. Have done strength testing on knots and sewwing and there is a lot of varability due to materials.
Second, plenty of folks never use splices; mountaineers, for example. Ropes that are well-sized almost NEVER break in the knots; it is chafe and cutting that gets them.
Another knot to consider is the figure-8 with back trace:
Sail Delmarva: Tired of splicing? Substitue a 90% Strength Knot.
Not too bad to untie unless really loaded hard and 85-90% strength. Absolutely reliable.
There are many other good choises.
There are at a few reasons to use knots in place of splices:
* Splicing used braided rope can be impossible and probably weakens it. Which leads to...
* A knoted halyard is easy to renew; just trim a few feet and retie.
* Splices can jam in some blocks.
* Knoted ropes are much easier to untangle than spliced ropes. On some tackles this is reason enough.
Not to say splices don't have their places; they certainly do. Try running a knot through a windlass.