The matter is that it wouldn't make sense to do it. It's certainly possible.
If you try building a large scale application (not merely a website or simple CRUD-style service), something as complex and demanding as a Google Sheets in pure html/javascript, you're going to reinvent a lot of wheels in the process and waste an enormous amount of time, for reasons (hopeful performance gains, and minimizing external requirements) that will not be strong enough to justify the time cost. More likely in the process of reinventing wheels, you'll lose a lot of your hoped for performance and simplification gains, as you create your own monsters and bloat.
Well, the issue these days is that JavaScript is becoming a serious security problem. Hopefully more and more people will just start blocking JavaScript outright, and this will just have been a misguided attempt to try and turn the web browser into a full blown virtual machine...
If you try building a large scale application (not merely a website or simple CRUD-style service), something as complex and demanding as a Google Sheets in pure html/javascript, you're going to reinvent a lot of wheels in the process and waste an enormous amount of time, for reasons (hopeful performance gains, and minimizing external requirements) that will not be strong enough to justify the time cost. More likely in the process of reinventing wheels, you'll lose a lot of your hoped for performance and simplification gains, as you create your own monsters and bloat.