Odd Soft 404's by the 100s

[Willfulone]

I am getting soft 404 errors (100's) in my GSC

These appear to be deleted or discontinued products (some deleted years ago) 

Any idea why 

and

How to get rid of them

I don't want to use an app to 301 because of the quantity

and

impact on SEO for that quantity of re-directs

Tks for the help

PS just finished blocking Web-Pixel-Manager@ and WPM@ in GSC but these issues were also there