That's just MMA mathematics. What exactly about Volkanovski makes him more skilled than other current champions who are dominating their divisions?
Two victories in a row against the second best featherweight of all time.
He's very well-rounded, very smart and one of the best stand up fighters in the sport (though i wouldn't call him a pure striker at all).
Let's look at the numbers for how he compares to the other champions when it comes to "hit and don't get hit" (amount of landed vs absorbed significant strikes):
Figueiredo: 3.38 L - 3.35 A
Volkanovski: 6.02 L - 3.31 A
Sterling: 4.84 L - 2.20 A
(Yan: 5.99 L - 3.55 A)
Usman: 4.63 L - 2.40 A
Adesanya: 3.95 L - 2.63 A
Blachowicz: 3.59 L - 2.79 A
Ngannou: 2.54 L - 2.04 A
Figueiredo on average lands
100.9% of what his opponents land on him.
Ngannou on average lands
124.5% of what his opponents land on him.
Blachowicz on average lands
128.7% of what his opponents land on him.
Adesanya on average lands
150.2% of what his opponents land on him.
Yan on average lands
168.7% of what his opponents land on him.
Volkanovski on average lands 181.9% of what his opponents land on him.
Usman on average lands
192.9% of what his opponents land on him.
Sterling on average lands
219.9% of what his opponents land on him.
Now in this metric, only Sterling and Usman are in front of him, however, Sterling - though officially the champion - got his ass kicked in his last fight.
Usman on the other hand, is currently the most dominant champion, but i don't consider an aging Tyron Woodley, nor Colby or Burns, let alone Masvidal to be on the same level as a prime Max Holloway.
Since this thread is about skill, i'd also say that though Volkanovski is very athletic, he doesn't rely as much on physicality or size as much as Kamaru Usman and he's significantly more sound defensively too when it comes to striking.
Hope this helps explaining my thought process.