Even though, hailstones have a small surface area and hit at quite some speed so wouldn't a higher force of pressure be exerted at the point of impact?
Nope This is getting a little technical, but both bodies behave as fluid pressure sources and it takes a specific footprint vs mass to cause visible damage. Thus the bird resistance just about washes with the hail resistance at the same conditions and hail is even more easily resisted on spinning fan blades at the higher aircraft speeds associated with climb and descent.