At Whiteboards.io (https://whiteboards.io) we are simply using React, CSS, DOM, and various ways to exploit the browser performance.

This approach is NOT perfect, but it solves problems like accessibility for example and it keeps us going.

The alternative approach like Pixi.js will work for you, but it effectively means building a browser inside a browser, kind of Adobe Flash type of solution.

IMO it is better to piggy back on the browser mechanics instead of building your own on top of the HTML5 Canvas. The fun fact is that the modern websites like Facebook or news front pages are far more complex and dynamic than pannable and zoomable canvas apps.