Definition - What does Doorstop mean?
“Doorstop” is an IT term for an obsolete program or piece of equipment, or anything that might take up space in an office. The idea is that these obsolete items are nothing but expensive doorstops, and their only utility would be to hold the door open.
Techopedia explains Doorstop
One interesting detail in the use of the term “doorstop” is that some definitions refer to obsolete or useless software programs, while others apply to specific devices and peripheral accessories. For example, someone might say “they did end of support for Microsoft 2000 years ago, and now it's just an expensive doorstop.” Here, the listener assumes a metaphor – that the doorstop would be composed of the box and CD that the software came in. However, the term “doorstop” can also be applied to the types of computer devices and accessories that end up in places like Goodwill and Salvation Army. It is easier to see how these items would function as physical doorstops, and how they would have little other value.