Problems created by the friction and heat can be trivially prevented with some routine maintenance once owners know that it needs to be done. The debris was causing enough friction and heat to actually melt the brush bar.

The bearing itself is a metal ring with ball bearings at the end of the brush bar.

The sleeve area where the hair and plastic melted together is not supposed to be a bearing surface. This means that it doesn't need to be very smooth so an unskilled scraping with a utility knife to remove the melted plastic and debris is good enough to make it work.

Use a utility knife to carve/scrape away melted plastic and debris until it clears the end cap. It doesn't need to be pretty.

Optionally, replace the whole brush bar if it's too far gone or the repair goes poorly.