Frankly, you're wrong. This is a fundamentally better plugin architecture that WP, and if you can't see it, then it's your understanding of security that's not right.
The post literally does that. it talks about how plugin access to core is handled. So to be explicit: if you don't see that as a very significant security improvement over WP's open world, then it may help to understand why. The post also talks about WP ecosystem downside due to this.
| "network:fetch" // ctx.http is available (host-restricted via allowedHosts)
| "network:fetch:any" // ctx.http is available (unrestricted outbound — use for user-configured URLs)
| "read:content" // ctx.content.get/list available
| "write:content" // ctx.content.create/update/delete available
| "read:media" // ctx.media.get/list available
| "write:media" // ctx.media.getUploadUrl/delete available
| "read:users" // ctx.users is available
| "email:send" // ctx.email is available (when a provider is configured)
| "email:provide" // can register email:deliver exclusive hook (transport provider)
| "email:intercept" // can register email:beforeSend / email:afterSend hooks
| "page:inject"; // can register page:fragments hook (inject scripts/styles into pages)
That are the plugin capabilities. I have no clue how it could replace any serious WP plugin. Of course it's secure ;)
> I have no clue how it could replace any serious WP plugin.
I'll repeat: your knowledge of security has a gap. You can specifically look up on "Principle of least privilege" as is widely used in apps and browsers too.