Why is my friends with benefits unable to let go of our situation?

I’m no longer interested in continuing things with him because I found someone that I’d like to pursue things with. I made it clear that I am done and I don’t want the distraction of this situation. I’ve blocked him on everything. I avoid him like the plague because whenever I run into him he desperately tries to get my attention, does the whole “can we talk?” thing which results in him trying to convince me to continue things, “can we still be friends, constantly looking me up on LinkedIn and TikTok. It’s to the point to where I’ve distanced myself from mutual friends because, I don’t want to deal with him.
Why is my friends with benefits unable to let go of our situation?
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