- You're locked into an online IDE if you want to use the PlayCanvas editor (which is the main selling point).

- Third-party dependencies are hard to integrate (for the online editor).

- You can't use different JavaScript languages (again due to the editor).

- I've seen lots of minor version changes that break too many things (not very stable).

- The editor had some major UI bugs back then (and probably still does).

Pros:

- Web-first library.

- Unity-like editor.

- Easy to debug/access things with only a link.

- Recently started to support WebGPU.

I've used ThreeJS, PlayCanvas, and BabylonJS in serious projects. I've concluded that BabylonJS is my go-to web-based 3D library from now on.

(Disclaimer, I used to work at PlayCanvas and still manage the Discord)

Just to help feedback on some points:

- ES6 Modules and NPM support is actively being worked on and should be ready by end of year

- Typescript support will follow after that

(Mark who wrote this now works at PlayCanvas https://forum.playcanvas.com/t/playbuild-a-compiler-and-pack...)

- If an minor engine release breaks existing project, the editor supports running and building with the last minor and patch release. Minor releases should never break existing projects unknowningly (shader chunks was the last (and painful) known big breaking change). The PlayCanvas team are usually pretty good at dealing with reported minor version breakages.

If you do take on another web 3D project after this work is done, hopefully this will help with reconsideration :)