webz.telegram.org and webk.telegram.org look amazing.
That's web apps done right. Small .js files intead of 20MB main.min.js crap.
The competitive angle is really delivering a fast/snappy/responsive experience on mobile or desktop. That in itself isn't going to save you, but it is an advantage if part of the sell is a high quality experience.
Re:interesting, for instance I just started experimenting with inlining all css/js into index.html (so far the js part is problematic), minifying classnames, and I'm curious if it'd be possible to even minify js module names etc.
Later I think they absorbed the X features into the core app.
I can't decide if I think it's an awesome strategy to launch a self-competing project, or if it just leads to terrible internal issues. I'm leaning more towards the former--I'm a huge believer in the instructive power of contrast, and it's a lot "safer" to contrast against another one of your own products than a competitor. You control much more of the "experiment", and you don't run the risk of cannibalizing your own users.
Plus, from an engineering standpoint, it forces you to have portable technologies and configs, and probably gives your team opportunities to learn from greenfield stuff that can then encourage refactors or other paying-down-tech-debt activities.
It's also just dang impressive that they're able to spin up multiple versions of the same app, and deploy them, and maintain them. That speaks volumes to me about their internal systems, build systems, resource allocation, etc.