If I had nothing of value or only antifragile things I'd just throw everything in an old backpack. The reason I own the pelican case is for when I'm flying with $15k of computers, camera gear, etc. If anything I'd see the pelican case as _increasing_ my risk of it being stolen (who puts some clothes and some deodourant and a toothbrush in a $500 hard case?), but massively decreasing my risk of physical damage which is way more likely.

The air tag isn't even really in there for "sophisticated thieves stole my stuff" purposes so much as "airline made me gate check it and now they've lost it" purposes. Though I imagine the air tag and some basic padlocks would definitely help my chances with most unsophisticated thieves.