For the most recent Pillow 10.0 release (2023-07-01) we stopped distributing 32-bit wheels for all platforms.
But we kept compatibility and are still testing 32-bit (Debian, Windows). We had a couple of issues opened, but no real pushback.
The decision was partly based on download numbers for the previous 9.5.0 release. (It had very low numbers for Linux 32-bit wheels (0.01% - 0.09%).)
The Windows 32-bit wheels had a bigger proportion but still low (0.90% - 5.63%), with the smallest share for Python 3.10/3.11, and highest for 3.8.
More details: Dropping 32-bit packages - #20 by hugovk
This suggests there’s fewer 32-bit Windows users for newer Python versions.