That's as useful as exporting your excel sheets into CSV or exporting your Google takeout backup. Yes you have your data, but can you do anything useful and continue working with it without a big deal of effort? I'd also like to continue working in the same learned workflow/method after I take my data.
I don't particularly want to spend ages trying to find "perfect" when roam is "good" enough. The chances of roam disappearing over night are pretty slim and I take weekly backups of my data from them. Worst comes to the worst I'll dump it into a directory and grep for what I'm looking for.
One more point: the exported data in markdown (and maybe in json too) is lossy. It's not just that the you can't use it out of the box, but that significant parts of it are missing as well.
