There are a few false equivalences in saying that, though.
First, VHL should *not* be compared to a Calendar class, that historically have always been quite amazing, the original Chronomancer was the best bar none when it came out, CDK was the first class capable of hitting for 7 digits damage, both Eternal Chronomancer and Corrupted Chronomancer can do similar, no class should be compared to Chronos because Chronos have always been a tier on their own, even if not all Chronos are amazing *COUGH*InfnityKnight*COUGH*
Second, tied to the above, VHL is a *free class*, while Calendar classes cost at minimum 6k ACs, or 20$+shipping, while VHL takes a lot of effort to get, it is still more accessible for people who are too young and have strict parents about online spenditures, or people who are not from the US, and can't afford to buy ACs so easily because their country's money is weaker than the dollar, which can sometimes make cost really prohibitive.
Third, ease of use and accessibility should be taken in consideration, VHL is mister "I am just going to hit 3, 4 and 5 until you are dead, 'k?", without any need for combos or the like, which makes me prefer VHL if I am farming a boss over ShadowWalker of Time, Eternal Chronomancer OR Corrupted Chronomancer despite owning all three, simply because I can play VHL without paying attention to the game, which is just not true for any of the current Calendar Class trinity, I normally only break out EC(still my favorite of the three big Chronos) if the boss has >600k HP, which is hardly every boss.
Yes, you can definitely say that Calendar classes are more powerful than VHL, but the statement should come with a ", but", outside of the realm of Calendar classes, VHL is still the best, with only LC holding up to it and being better for 300k+ bosses, and even within the realm of those classes, it's extremelly telling that all three of them have the exact same source(different calendars, sure, but still calendars), this tells me that we are not "moving the meta upwards way too fast", and I highly doubt we will get a non-Chrono class that will simply power creep VHL in the foreseeable future.