By the late 19th century, we already had general anaesthesia (developed starting in the 1840s), antiseptics (we’ve had them for centuries but their use became much more common in the late 19th century as the germ theory received broad acceptance), smallpox vaccine (very late 18th century development), a number of drugs (some known since antiquity others newly discovered), etc. Yes doctors were a lot more limited in what they could do back then, but even within those limits they saved people’s lives all the time. If your arm had gangrene, they could amputate it under general anaesthesia, antiseptics to try to prevent infection, and provide post-operative pain relief - which could literally save your life. Women with breast cancer received mastectomies (known about since antiquity but became much more common in 19th century, especially as general anaesthesia made the surgery more tolerable)-due to the lack of chemotherapy or immunotherapy, that wouldn’t do much for those with more advanced cancer, but if the cancer was sufficiently localised could be curative and lifesaving