Just to clarify, that is a real question, not rhetoric.
It is possible, but still difficult, to edit cells in-place. One example is the liver, a highly vascularized tissue (lots of blood vessels). This means that you can use a blood-based delivery method, e.g. blood infusion of CRISPR components + other compounds that allow these components to enter cells. Over time, more of the liver cells are edited and you can reach a reasonable proportion of the cells using this method using current techniques (40-90%). Note that for many diseases you would not have to reach 100% of the cells in order to have a positive effect on health.
There are a few labs working on better targeted delivery methods. In general the approach is to "wrap" CRISPR components in an envelope that is able to target specific cell-surface proteins for the cell type of interest.
Fascinating, thanks.
Basically an auto transplant with marrow
There's also more far-out ideas that might be viable involving permanently affecting the bodies biological machinery to improve it, like adding extra insulin producing capability to cells in diabetic patients.