The goalpost moving: the initial article is talking about porting a desktop client based program with a reasonable amount of views to the web. Now Facebook scale and quality UI isn’t good enough to demonstrate that React is a strong front end tool.
I also don’t see how the UI is particularly likely to cause issues to an insurance or banking company.
The BS: “most software of significant cost and size is serving a industry, not the industry itself”. This sounds smart but it has virtually no relationship to the main drivers of complexity behind the UIs in discussion, which is number of developers and number of pages. You cannot reasonably tell me Facebook doesn’t show React scales for UI engineering.