You need to distinguish safety properties from liveness properties.

Then you run into the problem of infinite loops, which nothing can prevent (sans `main { exit(-1); }` or other forms of losing turing-completeness), and are worse than crashes - at least on crashes you can quickly restart the program (something something erlang).

try-catch isn't a particularly complete solution either if you have any code outside of it (at the very least, the catch arm) or if data can get preserved across iterations that can easily get messed up if left half-updated (say, caches, poisoned mutexes, stuck-borrowed refcells) so you'll likely want a full restart to work well too, and might even prefer it sometimes.

I don't think runtime error handling is impossible in Fil-C, at least in theory. But the use cases for that are fairly limited. Most errors like this are not anticipated, and if you did encounter them then there's little or nothing you can do useful in response. Furthermore, runtime handling to continue means code changes, thus coupling to the runtime environment. All of these things are bad. It is usually acceptable to fail fast and restart, or at least report the error.