i doubt many people grind a ton of cobalt, most people probably even skip it only making drill/pick. Also, i'd prefer not to have to go back to something i didnt gave a in a long time just to make something extremly late game. Instead of cobalt i'd choose either chlorophyte (its plentiful yet you need lots of ore for bars, making mining it not entirely boring (because you almost always have some of it on screen, so you dont mindlessly mine to nowhere)) or some other material, maybe fallen stars?"Tired of grinding....early..material"
Did you not grind up a surplus of cobalt early on? If not, would you be mad if you have to grind something harder to get?