I hope you're right, but most reports do at least mention "exceeding maximum file size". That seems like a fairly basic error: what reasonable (national-scale) data storage formats would have an arbitrary file size limit?
We’ve actually had a similar issue in the US with some Electronic Initial Case Report documents (to be clear, we mostly rely on Electronic Lab Results-ELR rather than eICR in the US to count COVID numbers, so this hasn’t resulted in an under-count)
Rather than be a problem with the database having arbitrary file size limits, it actually was a problem with file size limits within network intermediaries. In most cases, the issue is less the limit, and more that the files themselves were too large because of how they were created. I don’t think this is the same issue as the UK (I don’t think they are using the eICR standard there yet), but it’s an example of how you could have a problem with file size limitations without storing data in Excel.
It's probably more the web server configured to only allow x MB maximum for file uploads. Or since the government has been shown to be incompetent, maybe it's the maximum size for email attachments..
A normalised SQL DB will have zero redundancy. It would also easily handle these data set sizes. The only reason Excel was chosen was because clearly some clerk just felt more familiar with the tool and didn't have the experience to know better.
The reality is though for storing this kind of relational data -- it's a solved problem -- SQL would have been the correct tool to employ.
Rather than be a problem with the database having arbitrary file size limits, it actually was a problem with file size limits within network intermediaries. In most cases, the issue is less the limit, and more that the files themselves were too large because of how they were created. I don’t think this is the same issue as the UK (I don’t think they are using the eICR standard there yet), but it’s an example of how you could have a problem with file size limitations without storing data in Excel.