It may feel that way due to the iterative nature of medical improvements, but over the past few decades there has been a consistent reduction in cancer mortality rates across most types of cancer [0]. Treatments really are getting better and more targeted. Immunotherapy has made huge breakthroughs. Combination treatments allow for significantly improved lifespans and better quality of life during treatments. There are a few cancers that remain hard to treat, but I have a lot of confidence that in the coming decades we will make strides in attacking them. That being said, I'm very sorry to hear about the pain you and your family must be going through. I've had a few close loved ones undergo cancer treatment and it was tough.
[0] https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac...