Research your choice of surgeon as that will have a real bearing on your outcome, there are good ones and not so good ones everywhere. Even if you just ask the nurses who they would go to, that'll tell you pretty much everything you need to know.
A women's surgeon was the one who told me I had cancer (I believe she was caught off guard and thought I knew I had cancer when I met with her). She was absolutely lovely and I'm told that she asks about me from time to time. A good friend is an anesthesiologist at that hospital and has said she's the best of the best. And she did my "cancer buddy's" mastectomy last year and my friend is super impressed with her scars (she still has reconstructive surgery after she has radiation). She doesn't do private, so to use her, I would need to be referred back to the NHS, which I don't mind doing.
I've sent my nurse a message asking if we can properly discuss surgery/healing time, benefits, etc. I think if "most people" recover in 2 months or so, I'm likely to go for it. If it's 6 months.... maybe not.
The person I know through work who has my exactly type of cancer, also Stage 4 when she was diagnosed in 2018, DID opt for the mastectomy. I struggle a bit to reach out to her as I don't actually *know* her. But I should, just to understand how she came to her decision. I know she elected to have it done, so would be interesting to hear about decision making.