It feels vaguely odd and especially ouroboroic to FAQ-find an Interesting Inquirer's question - soon enough will come the day when the sub is naught but orange flairs, with the other colour-flairs in hiding and eagerly pounced upon by those who wear orange...but I digress. On the Medieval Europe side, here's a few previous posts:
I highly second the same question on China, though - that, we don't see as often!
I can only speak for more ancient China (latter Han particularly it's dying years and three kingdoms of 180-280 AC) then medieval and the answer is... unclear but bandits were probably not an infrequent problem
Bandits could be used to describe armed groups that didn't quite fit the system, local groups that got conquered by more powerful and more traditionally legitimate leaders. Local rebels, a local leader who didn't submit to more powerful authority (or did so half-heartedly) self-defence groups, according to one dream a female lead group (we all know about them due to passing dream interpretation to show the skills of the dream reader, not the revolt itself), could all fit.
Some "bandits" like the Mount Tai group of Zang Ba o the Black Mountain Bandits of Zhang Yan were formidable forces with Zhang Yan's reach extending from Taishan into several provinces for a short time and embarrassing the Han in forcing a peace treaty/heavy bribes to behave and a local power in the early stages of the civil war.
The focus of historians was not on the common man but on political affairs and the powerful. A fire at the palace? An omen, public expensive to fix and likely to be recorded. A fire in the capital? Of no matter. Bandits around? Not a problem. Bandits capture the family of major official? Might be worth nothing. Particularly if something happens, a bit of trickery, a valiant rescue or family refused to pay the ransom out of principle and so family member gets killed. The times a family member was paid for and returned I don't often come across, one does wonder how many times such things happened but simply were quietly not recorded since it would seem to be so unremarkable for such an event