Detected by the asv benchmark suite. Impacts the fit and transform methods of MiniBatchDictionaryLearning
https://scikit-learn.org/scikit-learn-benchmarks/#decomposition.MiniBatchDictionaryLearningBenchmark.time_fit
https://scikit-learn.org/scikit-learn-benchmarks/#decomposition.MiniBatchDictionaryLearningBenchmark.time_transform

The regression seems to be due to the support of float32 by this estimator done in #22002.
The benchmark uses a float32 dataset, so the most probable cause is a leftover copy somewhere, because we'd expect that a benchmark that used to cast into float64 and run everything in float64 is slower than running everything in float32 from the start.