I have a simple rule: If the app requires real time updates and push, then SPA it is, but you can also mix server side rendering with SPA's aka micro services,

I have a simple rule: If the app requires real time updates and push, then SPA it is, but you can also mix server side rendering with SPA's aka micro services, eg the "chat" can be it's own component. The argument for SPA's is that they perform better, but I don't find that to be the case with all the bloat on real world "apps". Browsers are good at rendering static content, and a server rendered site will perform well even on low end mobile devices. With todays hardware the server can render even the most complexed site in less then a millisecond, and with todays networks the latency, often as low as a few milliseconds is imperceivable and even faster then clicking around in something using a JS framework.