How can a patient still have cancer after lumpectomy? Cant find good surgeon (even if rich celebrities)? Not fair to need mastectomy vs radiation, etc

Breast neighborhood. It's not the surgeon, it's the bad breast neighborhood that allows cancer to return. Cancer cells can sneak away from the tumor before surgery, which is why radiation therapy is necessary after any lumpectomy. Even with radiation, there is a higher chance of cancer returning after a lumpectomy compared to mastectomy. You're right, it's not fair. We need better treatments for breast cancer.
Breast Conserving Rx. Many well-designed studies have proven that lumpectomy alone is insufficient local rx of breast cancer due to high rates of local recurrence; radiation therapy (rt) to the breast is necessary to reduce this rate to acceptable levels. Unfortunately, some people are not candidates for rt, in which case mastectomy is necessary. Second opinions are often very helpful to clarify these issues.
? One can go with lumpectomy alone if they accept a risk of 3-5% per year of local failure leading to breast loss, and a loss of the survival benefit of raiotherapy. However, all cases are not amenable to lumpectomy (size to big, persistent postive margins). There are plenty of good surgeons and radiation oncologists that will work with you.
Breast cancer. Multiple clinical trials over decades show that lumpectomy alone is not adequate treatment for most (not all) patients, because there is often more cancer cells in the breast, beyond the "lump".
No good answer. Even mastectomy does not preclude previous circulating microscopic cells. The body has natural killer immune cells that hopefully can eradicate these small amounts of cancer cells given other appropriate therapies.
Microscopic disease. I hear your frustration. Expert surgeons will remove the macroscopic disease ( what he/ she can see by his/ her eyes), but the nature of the beast is microscopic disease that can not be seen by naked eyes. Radiation can sterilize this effectively similar to mastectomy. There is some more recent experience with partial breast radiation that is promising.
Lumpectomy. An expert physician in breast cancer is necessary to give the statistics necessary to decide on a lumpectomy. A good expert gives the positives and negatives of a treatment, likelihood of a recurrence. Not all surgeons are equal in their ability to treat breast cancer. Always, get a second, or even a third opinion. Educate yourself, have a family member become a great source of info for you--read.