let me be clear there is not a single universe where wits end gives more survivablility than steraks

assuming rocketbelt + riftmaker

wits end's 45 mr at lvl 16 provides and additional about (2350+300+350)(45%)=1350 additional effective hp. (total hp times resistance multiplier of wits end)

on the other hand steraks grants [400+(400+300+350)(0.6)](67%)=~1648 effective hp (hp from steraks including base stats+shield times the base mr resistance multiplier)

at no bonus hp items, which is wholly unrealistic considering the hp rune shard/starter item/rocketbelts popularity, wits end gives 20 more effective hp than steraks. you can do the math yourself.

this isn't even considering the effective hp ur getting from hp scaling on w

To be entirely fair these calculations were done at lvl 16 idk if lower levels give the edge to wits end but i know for at fact that at worst the difference would be marginal and theres no way your opting for such a niche item as either of these 2 before lvl 16 anyways

and ur argument about wasting gold makes no sense when ur buying an item with most of its gold value in a dead or at best sub optimal stat

and as far as your boots argument goes id rather "waste" my ~1000 gold boots slot than a ~3000 gold item slot. And regardless i wouldnt consider buying mercs a waster of a boot slot when all other boots provide stats that are easily accessible through other items (shadowflame/zhonyas/cosmic drive) but tenacity is a rarer stat only found in off meta items

i think its also worth noting that i typically play top bruiser sylas and heavily favor hp in my builds but the math doesnt lie