Simpler, rule-based approaches, like the Jaccard index, are highly competitive for small data sets, but as more data becomes available, they lose out to more sophisticated approaches.
and confirming a widespread assumption in Machine Learning, deep learning approaches come into their own, and its performance surpasses all other approaches, only when a sufficiently large amount of training data is available, containing above 30,000 pairs of sentences with a 50/50 split between duplicates and nonduplicates.