AIUI, the kinds of eye damage being warned against mostly don't cause immediate injury, but cause serious symptoms later in life. Things like macular degeneration, and damage to the lens and cornea. These also have additional genetic and environmental risk factors. When those symptoms appear, they can't be perfectly linked to staring at the sun, the same as skin cancer can't be linked to a specific case of sun burn. But excessive sun exposure still raises your risk of developing skin cancer significantly, and staring at the sun raises your risk of eye damage.
As someone who's grandparent had macular degeneration, and lost her sight 20 years before she died, I've been recommended to always wear sunglasses when outside on sunny days by my opthalmologist. Not doing so isn't going to make me go instantly blind, but it adds to the risk, and adds cumulative damage.
And risk to eclipse glasses are mitigating is from staring before and after totality, not during totality.
Aside from that, you'll also get a better view of the corona using eclipse glasses and be able to look longer with less eyestrain and resulting headaches.
