I'm luckily not in a situation currently where this applies to me, but I can elaborate on the couple of experiences I have had with dropping "dead weight"...
Day 10: Someone you need to let go, or wish you didn't know.
We've all had them - that friend that becomes a frenemy and then maybe just becomes toxic. Unfortunately, they don't always realize that's how you see them. That's when difficult conversations have to be had. I've had to have that "conversation" twice in my life. I say "conversation" (with little air quote fingers) because it was more like an email from me explaining I didn't want to be friends anymore. This may not be the method everyone would prefer, but it works for my in my favorite ripping-off-a-bandaid kind of way. It's not fun, and it's not easy, but in both cases, I felt it had to be done.
The first was a college friend. We'd been very close our junior year, then drifted a wee bit after she graduated (I did two more years due to changing majors and schools), and then we became coworkers at my first job. We liked working together and we were fine and I thought we were tight. And then she got engaged. And she asked our whole crew from college to be her bridesmaids... except for me. She was insensitive - in my opinion - about it. She'd ask me what I thought about bridesmaid dress designs, wedding plans, and bridal party gifts. She never had a conversation about why I'd been excluded. For the record, I didn't feel I deserved to be a bridesmaid, just that I thought it was hurtful that I was the only one left out. It just showed me that our friendship clearly didn't mean to her what it meant to me. Later in her planning, she excluded only one of her fiance's five siblings (his sister who didn't end up attending the wedding at all, she was so hurt) and I noticed a pattern of thoughtlessness. I ended the friendship just under a year after her wedding. It just had become more hurtful than mutually beneficial and I was ready to cut ties.
Recently, I mentioned that I needed to sever myself from another friend, and I did in August. We had been coworkers at the job before my current one and kept in touch since we both left the company. She was supportive while I was planning my wedding, and it was also during that time that she was pregnant with her son. However, there was always something that bothered me about her and that was the way she was so jealous and hateful in the way she spoke of her step-children, as well as controlling of her husband. She would complain to me endlessly about her fights with her husband, mostly involving her step-son and how she wanted the kid (who was 15 when they married) out of her home. She fully intended to kick her step-son out of their house when he was 18, without any regard for her husband's wishes or where the kid would go. Basically, she wanted to have her little family with her husband and their son, and her step-kids could disappear into thin air for all she cared. Anything else her husband did that wasn't exactly how she wanted resulted in a fight, sometimes leading to them not speaking for days. I tried to respectfully tell her when I thought she was being ridiculous but it was met with, "well, you don't know. Dan doesn't have kids, he doesn't have an ex wife."
From my perspective, her life was just chaos, and most of it was caused by her over-reacting. I did like her, and I liked hanging out with her, so for a while I justified it with "sometimes nice people do shitty things," but then I realized that the things she was doing reflected an ugliness inside her. At some point, I just grew exhausted. So I wrote her an email one day and - very successfully restraining myself and my true opinions - told her that I didn't think we should communicate anymore. It's been one of the best decisions I've made. My weeks are much less drama filled (she literally fought with her husband weekly) and I don't constantly feel like I'm biting my tongue.
It's not easy letting a friend go, and I'm thankful that the friends I currently have in my life are true and wonderful friends. I prefer quality over quantity when it comes to friendships, and it's lead to me having meaningful and long-lasting relationships in my life.