So technically, it took you 4 years of play time to gather enough essences to *almost* cap crafting in 8 hours. Doesn't sound like you maxed crafting in 8 hours to me. Your definition of "can be done in 8 hours" and my definition are very, very different. Additionally, you acquired thousands and thousands of RNG items during that same 4 year period which further dilutes the value of crafting and the incentive to max it as you likely found some really good, if not perfect, RNG items.
Ponder the following scenarios before deciding to stick with the claim that it's easy and can be done in 8 hours.
1) If a level 1 player new to DDO were to decide to start crafting right after character creation, could they cap it in 8 hours? No. They couldn't even cap it in 20 hours because they have to spend more time than that acquiring the essences in some manner.
2) Let's assume said new player leveled to 20 as a first-lifer and stockpiled all the essences from chests and deconstructed all of the RNG items they looted while leveling. Once they hit level 20, if they went to the Cannith Crafting Hall, could they cap out all three crafting schools in 8 hours? No.
A) Even after 20 levels of missions, they wouldn't have enough essences at that point to max crafting no matter how many hours they want to spend clicking Combine.
B) Without buying P2W crafting XP potions from the store using TP that would be sorely needed for other things and/or waiting for one of those rare +30% CC XP weekends, even if they had managed to acquire enough essences to max crafting, they would zero out the xp gained from all possible shards before capping and have to TR to be able to further progress.
In summary, the only way to literally max crafting in 8 hours from start to finish,
*including* the time require to acquire enough essences to do so would be to exploit and dupe essences.
Additionally, the only way to cap crafting in one life without TRing to reset the xp per recipe limitation is P2W or wait an indeterminate amount of time for that rare CC XP bonus weekend. Thus, you need to also include the time it takes to level from 1-20 or 15-30 and TR to the total time required to max crafting without P2W.
You shouldn't cherrypick the convenient parts of something when trying to prove or disprove the whole thing.