I mostly agree regarding GL's programming model, but tbf some problems have been fixed by WebGL2 (much better validation and error reporting - e.g. very helpful error messages right on the browser console - and it's probably the least buggy and most portable 3D API implementation of them all, including the current state of WebGPU.

For teaching I would generally use the web browser via WebGL2 or WebGPU, just because those APIs require much less boilerplate in the browser environment to get to your first triangle and the edit-test-loop is pretty much instant.