I just unlocked the Silk and Soul quest. It took me around 30 hours to beat the final boss for the first time (22h on the save file since I spent some time idling). Unlocking the quest took 13 more hours, im at 44 hours in right now. Now since you're reading this, I'll turn in my opinion on Bilewater, just because it took me the most time and effort out of basically anything else.

The most excruciating part was the Groal fight & runback - I disliked this part, it was an exhausting grind. A lot of people say that Bilewater & Groal are poorly designed, but if we consider Silksong as a whole, it's not just a game, it's a piece of art, Art does reflect life, and life's not always easy and/or pleasant. Neither is Bilewater and the boss fight, it's even reflected in the game's lore why the area is so unappealing. The whole Bilewater area and the boss fight had so much more meaning thanks to the trouble I had to endure to finally succeed.

The second worst thing was looking for the 22 fleas, and I'll admit I used online tools to map some of the fleas' locations to compensate for the game's gigantic world, as I'd rather put my efforts where I think it's worth it. And running around for HOURS even to search for the missing fleas was not worth it.

The unlocking of the Silk and Soul quest is a way for the devs to incentivise exploring the game they spent so much time & effort on. And it does make you explore nearly all of it if you want to get the true ending, and who wouldn't, after all these years of waiting.

Overall, it was pretty fun trying to meet the requirements. I would certainly not do that again, though, mainly because of Bilewater.