Yes another analysis showing how poor t-SNE and UMAP are. Only 60% of the ten nearest neighbors are even among the 100 nearest neighbors in high dimension.
How many such demonstrations will it take to convince people to abandon these plots?
tSNE/UMAP preserve neighbors in a "soft" sense:
Yes, tSNE recalls only ~30% of neighbors exactly.
But ~60-80% of the 10 nearest tSNE neighbors are among the 100 nearest true neighbors! So even if some tSNE neighbors are not next-door neighbors, most are "from the same block".