Can you be more specific? It clearly mentions encryption-as-a-service and secrets generation as advantages of Vault, among others.
The point of the comparison is not to have an itemized list of every feature, but to compare the most important features and tradeoffs at a high level. It includes the disclaimer that Vault could be better for some more complex use cases (as I have also done here in my reply to you).
Your "Quick Compare" table has EnvKey winning on everything and doesn't mention anything about the fact it only does about 10% of what Vault does. The 90% of stuff that Vault does that EnvKey doesn't, gets one sentence in the advantages list and is downplayed in the conclusion.
A fair comparison would point out that EnvKey only does a small but important part of what Vault does, and explain why it does it well. Somebody who didn't know either piece of software, might read your comparison and get the false impression that they had equivalent functionality.
I don't expect you to agree, because that would mean you had to change the page to one which maybe doesn't convert so well.
I think your “90%” is quite unfair as EnvKey also has a lot of features that Vault doesn’t have, and the comparison is focused specifically on secrets management.
Vault has some long tail infra/enterprise features that EnvKey lacks and perhaps those are relevant to you, but a lot of them aren’t really secrets management per se, and for the core objective of managing secrets and config, EnvKey has a lot in terms of de-duplication, automation, and UI/UX/DX that Vault lacks. But for sure it depends on your use case.
Of course we are going to be somewhat biased, but everything in the quick compare section is backed up below. On security, EnvKey has end-to-end encryption; Vault doesn’t and requires trusting the host server. EnvKey is clearly easier to set up and use. EnvKey has an MIT license. EnvKey fits into a local development workflow and keeps config in sync much more effectively.
For sure you could write something that gives more attention to Vault’s specific strengths, but I stand by the comparison as broadly accurate.