It depends on your expectations. For example, you could construct a page on https://blog.example.com/my-summer-vacation-2020 and load all resources in the form of static/style.css, static/comments.js, media/header.webp and so on. As long are you're aware of the differences and the way your web server resolves static content, you can pick either, whatever you prefer.

I have no idea what Vercel, Render, and Azure Static Web Apps even are, but you should obviously be aware of their limitations when using them to host HTML. I'm sure there are plenty of other behaviours that differ between them and there's hardly any universal truth to be found in the decisions some big corporations once made.

This article seems more about the default slug-to-content resolution algorithm from a bunch of cloud providers than it is about trailing slashes.