Hand guards (that is, SUBSTANTIAL hand guards with metal backbones, not merely plastic wind deflectors), when installed and adjusted properly, can PROTECT brake and clutch levers from breakage in the event of a fall.
Certainly, some hand protection is offered also, in the event of tree trunk, root, stone cliff, etc. collisions.
Many satisfactory makes and models of hand guards must exist; I've found Tusk handguards versatile regarding installation, affordable regarding price, and . . . effective in protecting levers, hands and fingers in crashes. YMMV.
KLRista low-cost expedient: I've seen OEM KLR elephant-ear wind deflectors screwed to bare-bones aluminum strip hand guards. Doesn't look bad, and should protect effectively as well.
I bought Tusk spoilers to go with the hand guards; at about $ 12 a pair, replacement is easy and affordable in the event of road rash.
Tusk "D-Flex" hand guards on KLR250 (KLR650 installation essentially identical), from Rocky Moujtain ATVMC: