I re-read an old thread on this topic, and have nothing to add specifically on the question of
insurance of gear, except that I have never had any insurance for it. But the closest I would say
is what has been said above: Don't take more than you need on (any, not just OS) trips away,
and keep it "surgically attached to yourself". And take other practical steps to ensure that you
retain possession of your stuff. For damage, I have just been prepared to (swear at myself and)
wear it, but happily, none has happened.

I can attest that twice I have had swarms of young locals targeting me as an obvious "tourist"
and person-handling my stuff, but some firm reaction and some sharp imprecations in the local
language resulted in their desisting. (Note, I'm not claiming any definite cause-and-effect, but
just that it happened like that.) And never forget about pick-pockets!

(OK, I've enjoyed exceptions to the rule above when staying with friends or relatives, confidently
leaving some gear in the house while going on an outing, but never in the likes of [h/m]o[s]tels.)

(A bit of a rave...)