The problem is not that it doesn't use it, the problem is that this import creates a circular import.
The circular import became evident when working on PR#9022 adding
from matplotlib.table import Table tomatplotlib.backend_tools.py gave the following error

  File "histogram_cumulative.py", line 39, in <module>    import matplotlib.pyplot as plt  File "/home/fariza/workspace/matplotlib/lib/matplotlib/pyplot.py", line 29, in <module>    import matplotlib.colorbar  File "/home/fariza/workspace/matplotlib/lib/matplotlib/colorbar.py", line 36, in <module>    import matplotlib.contour as contour  File "/home/fariza/workspace/matplotlib/lib/matplotlib/contour.py", line 22, in <module>    import matplotlib.text as text  File "/home/fariza/workspace/matplotlib/lib/matplotlib/text.py", line 33, in <module>    from matplotlib.backend_bases import RendererBase  File "/home/fariza/workspace/matplotlib/lib/matplotlib/backend_bases.py", line 68, in <module>    import matplotlib.backend_tools as tools  File "/home/fariza/workspace/matplotlib/lib/matplotlib/backend_tools.py", line 16, in <module>    from matplotlib.table import Table  File "/home/fariza/workspace/matplotlib/lib/matplotlib/table.py", line 34, in <module>    from .text import TextImportError: cannot import name 'Text'

PR Checklist

Has Pytest style unit tests
Code is PEP 8 compliant
New features are documented, with examples if plot related
Documentation is sphinx and numpydoc compliant
Added an entry to doc/users/next_whats_new/ if major new feature (follow instructions in README.rst there)
Documented in doc/api/api_changes.rst if API changed in a backward-incompatible way