PageRank sculpting via nofollow stopped working as imagined because Google changed how nofollow handles equity, so the value you try to “save” is not handed to your other links, it is effectively lost. The whole technique rested on a plumbing picture: equity flows like water through your links, and by capping some links with nofollow you would dam the flow and redirect it into the pages you care about. Google closed that loophole, and observed behavior since is that the dammed equity does not pour into your remaining links, which is the precise expectation sculpting was built to satisfy and the reason it fails.
The first half of the mechanism is the nofollow change. Before, a nofollowed link was thought to remove itself from the division of a page’s outgoing equity, leaving more for the followed links. After Google’s change, nofollowing a link no longer concentrates that share onto the others, the would-be-saved equity is simply not redistributed, it dissipates. So the act that sculptors rely on to reroute value does the opposite of nothing useful: it removes a normal signal and gives you no compensating gain, which is worth confirming against current guidance but has held for many years.
The second half is that link flow was never the simple plumbing the model assumed. Real ranking signals are far more holistic than a fixed pot of equity split cleanly across links and rerouted at will. The system weighs relevance, context, and the overall structure of a site at once, so the tidy image of damming and channeling a single quantity through pipes does not match how authority actually moves. Even if nofollow behaved as sculptors once thought, the underlying picture of equity as a controllable fluid would still misdescribe the machinery.
So abandon sculpting and manage equity through the controls that actually respond. Shape what gets emphasized through site structure, link to important pages more and from relevant contexts, and keep low-value pages out of the index with noindex or out of prominence through where you link them. Drop the plumbing model entirely, because the technique built on it does not redistribute value the way it promises, and the levers that do work are structure and indexing, not nofollow.