Benching is what happens when you start dating someone you think is nice and who has potential, but you're not crazy about them.
Modern relationship practices among millennials include ghosting, gaslighting » , stonewalling » and benching among others.
These idea of these things may have been in existence before now, but this generation is putting cool names on them, making them easier to understand and more recognisable by people who should know about them the most.
According to Urban dictionary, benching is what happens when "you start dating someone you think is nice and who has potential, but you're not crazy about them.
You don't know whether to keep dating them, or dump them and move on to the next one... so instead of going for either of the above polarized options, you put [the person] in your mental 'maybe' folder and 'bench them' so you date around to see what else is out there."
In essence, benching is the emotional manipulation of people into staying interested in you.
If you find someone else better, the benching could easily turn to ghosting as there'd be no need to go back to explain or say anything to them. The relationship is left to just fade away like that.

How benching affects relationships
The practice of holding out for better while putting someone else 'on hold' may sound quite selfish but really, it is difficult to condemn someone looking out for themselves and what's best for them.
However a line has to be drawn when one person leads the other on for so long, refusing to commit while keeping their options open all along while the other has his or her hopes solely pinned on the possibility of a relationship with the person who has already benched him or her.
What could also happen is that during the search for something better you may lose the great person who could have made a great partner. And you know what's worse? The search for something better sometimes produces nothing.
That's like trying to trade something valuable and getting nothing in return.

https://www.nigerialog.com/romance/what-'benching'-means-and-how-it-affects-your-dating-life/new/#new