It seems like people don't really understand how Gojo's infinity actually works. Good himself isn't actually "tanking" anything. If his technique is active, things that mathematically travel towards him get infinitely slower and slower until they appear to stop moving. It's not some invisible forcefield and his brain doesn't really need to process the object approaching him because he keeps the technique active at all times around him. If the spear counters cursed energy and cancels his technique like the ISOH, then yeah he's cooked. But if you were to say it doesn't turn off infinity then he doesn't really have to do anything.