Is it required or optional? Why back to level1? New effort for leveling up?
each Ascension gives you more farming capabilities. for me it is a requirement if you will farm for crystals mythstones and eternals
optional. there are players who do not Ascend for Perks, and they do well. Perks are for players who want more loot when they farm. some players only Ascend 1 or 2 characters, and just max level the others with out Ascending. going back to level 1 is a part of getting the Perks, as Level 99 is the highest level you can achieve. so to get the Perks, you have to go back to level 1 after getting a Perk, and it is up to you if you stop getting or continue getting Perks. otherwise, the max level would be around 693, and that would really mess up some parts of the game, especially when you respec stat points. it’s 98 now, but used to be almost 300, and would be around 1800 points to respec if you didn’t go back to level 1. you would be pushing a lot of buttons.
Most perks can be gained by higher item equipment, but perks help you climb to higher levels etc. Catch 22