@jprust Here is an article from the National Kidney Foundation which has a lot of very useful information. As you can see, they say at about 15% we are severely compromised in getting all the toxins out of our bodies. I know for me, starting dialysis at 14%, it was still a few weeks before I could realize a difference. Our bodies learn to accommodate the declining function of our kidneys, and we don't realize how much we are feeling poorly until we are feeling better. Hope that makes sense!

Face it, getting to the dialysis stage is a big deal, and even now many doctors downplay it. I think those who push for it at higher eGFR levels are those who have a family member/friend and saw it firsthand, or have concrete testimony from patients.
https://www.kidney.org/atoz/content/dialysisinfo
And this excellent article from My Health Alberta [Canada] explains things well, too! Expand their bullet points to read some great information!
https://myhealth.alberta.ca/Health/Pages/conditions.aspx?hwid=abo2705
Ginger