'Steal' is suppose to be one of those things where if you have it, great, you can potentially pick up some useful items. If not, eh don't sweat it too much, a better item or the exact item will come along soon enough. Stealing really is only necessary if you're one of those people who either have a specific goal in mind like doing challenge run or are trying to get 100% items.
Though personally, I'm the opposite. If a 'steal' command or equivalent is in the game then that ability or the party member that has it almost becomes mandatory for every fight. I'll steal from everything so not to miss anything.