Tespia is now OPEN!

It doesn't. You're still gonna get etc drops and quest items from monsters regardless of how much higher you are. It's only equips, use items, and mesos that are affected.

Some quests require Use items. Example off the top of my head: Sap of Ancient Tree. Drops from level 14 Dark Axe Stumps. Required for level 45 quest Jane the Alchemist. By that point you can only get it from Stumpy (because it's a Boss), which you can fight once an hour, and does not always drop it. Oh joy.

But seriously, what's the idea of making us unable to use our high-level chars to hunt for recipes, scrolls, lower-level equips to fuse or disassemble for crystals... You don't like botters? Send GMs after them. This anti-bot measure is anti-all-players as well.
Nobody actually trains where the good stuff drops, especially now with the oh-so-godly Monster Park, so by the time someone is high enough level to feel they have some leisure - or need some money - they can't hunt anywhere but only within a narrow level range. Sorry, but that's horrible.

Too bad Nexon has already reached its quota of "listening to the players" for this year (decade?) and there's no way to fix it. Oh well, good job forcing high level chars off the game. Nothing to do but a couple boss runs a day (and ©HT still glitched and CWKPQ still closed... oh joy!)