This is a great example of "fighting the framework". React + SVG got them from nothing to a working product. But then they had to rewrite completely to solve problems in the product because the framework no longer fit the product. I've seen this so many times.
But it's hard for people to believe when they start out and choose the "perfect" framework for their product:
"you will eventually have to rewrite your entire product because that's easier than fighting the framework to make it do what you need"
"no, we won't, this $framework is flexible enough to do whatever we need"
"OK, good luck"
2 years later:
"we're rewriting the product completely because $framework wouldn't let us do $thing"
Not that I'm advocating for not using frameworks, just for people to realise that eventually (almost) everyone fights the framework and rewrites. And the more the framework does, the earlier the fight begins.