It's a complicated issue because it of course depends on how reliant a product is on SEO. Maybe certain pages that bring in views from search engines shouldn't be part of the same client-side application in the first place, but if it must be then the developers have to decide if they're building a SPA to actually hand off workload to the client or because they want to use React. :)
But to the point of the person you were replying to, we definitely overcomplicate web development these days. There are some good reasons for this, like the fact that there's so much competition to contend with(so we all feel like we have to be rockstars), but it's good to remind ourselves that the end goal shouldn't be focused around the tools.
