I'm not a native speaker, I tried googling and translating and still did not get what "ablative" means. Do you mind explaining like I'm 5 what does it mean please..
> Ablation (Latin: ablatio – removal) is the removal or destruction of something from an object by vaporization, chipping, erosive processes, or by other means. Examples of ablative materials[clarification needed] are described below, including spacecraft material for ascent and atmospheric reentry, ice and snow in glaciology, biological tissues in medicine and passive fire protection materials.
The poster is saying that a case can wear out and be replaced without damage to the phone. You can let the case take all the damage, then get a new one. But if you let a phone take all the damage (even if it's a tougher phone), you can't remove that damage.
Young kids can go through multiple cases each of which look like they have been run over, but it’s relatively common for adults to replace a case.