...backups?

This issue is not unsolvable at a technical level, but it probably is at a political level. Someone would have to determine and write up what is good enough now (on sane setups), and then Unix kernel people would have to say 'enough, we are not accepting changes that break this de facto standard'. You might even get this into the Single Unix Specification in some form if you tried hard, because I really do think there's a need here.

Or we could just have everyone perform regular backups like they already are/should be doing, and decide that if systems are crashing so frequently as to lose data often enough, trying to "fix" this "problem" by adding what would likely be another mass of design-by-committee complexity to filesystems is not addressing the cause but only its symptoms.

Then again, with over two decades of experience using the FAT filesystem and never a single instance of unrecoverable data loss despite sudden crashes while hearing countless tales of others corrupting their data frequently even when using far more complex and "robust" filesystems, it makes me wonder why I don't seem to suffer quite the same problems...