The first question isn't "log in".
It's "how do you want to use this?" Read to me. Larger words. Simpler view. Just read. The mode isn't buried in a settings screen. It's the front door, and it can be changed at any time.
The same content renders four different ways. A participant with a cognitive load can pick "Simpler view" and see three things per screen instead of ten. Someone with low vision picks "Larger words". Someone using switch access picks "Read to me" and never types.