Nah its totally doable with the actual endgame gear, ppl just need to really have a gear (enchanted and good stones)
When we got makarna we just got a 2nd option to be endgame geared: Blessing hyperion or farm Makarna with base hyperion/EB/whatever and get Beritra set since they are very similiar (Beritra: https://aioncodex.com/en/item/110551211/ Blessed hyperion: https://aioncodex.com/en/item/110551096/ for comparison)
Anyway, TOTALLY agree. Always loved Makarna, and its quite more challenging than any other PvE content which is something we need now to appreciate the easy PvE we have atm.
As for the loot and rewards ofc no makarna gear, would be overkill.
Maybe skins, chance of tempering, Beritra wings (which we already have but locked into PvP event), or even extend materials, composite boxes, medals and ofc GP with same amout as IS. Anything related to endgame needs is ok!
.........maybe add a nerfed version of Narakalli too? would be the best thing ever