While there is some percentage of people who these compound movements would be bad for, the beauty of the progressive overload is that you can start incredibly light and strengthen your body overtime. When you compare older people who deadlift versus those who do not, you will often see a great difference in back pain and overall mobility. And for most people it is never too late to start.
And planks/step ups may be great, but they are no replacement for deadlifts and squats.
And planks/step ups may be great, but they are no replacement for deadlifts and squats.