The dashboard has to deal with a complex data integration problem, with different sources with differences in completeness, accuracy, age, and granularity (at many levels), daily corrections in past data, changes in data structure and semantics over time, large data volume, 4pm traffic spikes. Moreover, an API that allows you to select different metrics for different areas. Being able to simply write a SQL query or update and have it be fast regardless of volume is quite a life-saver if you have a tiny (mostly 1 person) team and development speed/adaptability is essential.
I think the point was that the analyst needs to do that, but the frontend doesn't really need to - it could render a bunch of statically aggregated data and the spikes become another CDN problem.
See the other comment about the Dutch dashboard. Covid data isn’t changing that quickly. Having the frontend render something more static simplifies the design. No sql queries are even needed and you don’t need to scale out your database.
Well the Dutch site takes much longer to load. All these comments are (rightfully) discussing the back end being incredibly over-engineered, but 99% of people do not care about that. They care about how quickly a page loads, which the gov.uk site does much better.
I guess that implies that using Next for a "static site" is not a great idea.