The last decade has seen an increase push in what Google started calling "Zero Trust"[0] and dropping VPNs entirely. The issue being that once someone got into a VPN it was much, much harder to prevent them from accessing important data.
So everything "internal" is now also external and required to have its own layer of permissions and the like, making it much harder for, e.g. the article, to use one exploit to access another service.
Does having a VPN/intranet preclude zero trust? It seems you could do both with the private network just being an added layer of security.
The zero trust architechture implies (read: requires) that authentication occurs at every layer. Token reuse constitutes a replay attack that mandatory authentication is supposed to thwart. Bypass it and the system's security profile reverts back to perimeter security, with the added disadvantage of that perimeter being outside your org's control.
The big problem with the ZT approach is that smaller shops don't have a lot of developers and testers (some maybe with a security inclination) to be certain to a somewhat high degree that their app is written in a secure manner. Or be able to continuously keep abreast of every new security update Microsoft or other IdP makes to their stack.
It is easy for Google/Microsoft and any other FAANG like company to preach about Zero Trust when they have unlimited (for whatever value of unlimited you want to consider) resources. And even then they get it wrong sometimes.
The simpler alternative is to publish all your internal apps through a load balancer / API gateway with a static IP address, put it behind a VPN and call it a day.
Zero trust is a good concept turned into a dumb practice. Basically people buying Google's koolaid for this forgot about "defense in depth". Yeah, authenticating every connection is great, throwing a big effing moat around it too is better.
The other thing is most companies are not Google. If you're a global company with hundreds of thousands of people who need internal access, moats may be non-ideal. For a business located in one place, local-only on-premise systems which block access to any country which they don't actively do business with is leaps and bounds better.
I don’t see that really as an argument for this. You still should use VPN as an additional layer of security, assuming that you use some proper protocol. Then zero trust applies to internal network.