Pixel 6a doesn’t appear to have the enhanced Magic Eraser feature right now
The Pixel 6a will apparently offer an enhanced version of the Magic Eraser object remover feature which should also let you change the color of objects to they blend more seamlessly. The hands-on video indicates that the new functionality is not live yet.
Even though the Tensor chip might not be the fastest SoC around, it’s plenty fast, and benchmarks don’t necessarily accurately reflect the real-world performance anyway.