Eyesight will disable itself but not interfere with driving. No different from abs disabling itself if an abs sensor, sensor wiring, damaged reluctor or the abs electronics fail; you will always have braking, locking up a wheel or two in panic stops. ABS
is an enhancement to power assisted brakes. Eyesight may be considered an enhancement to driving safety, but will not prevent a driver from using common sense driving techniques along with experience to drive safely.
Eyesight may have disabled itself for a number of reasons; temporary fogging of camera(s), electronic interference, weather obscuring cameras and electronics discerning danger from normal driving, heavy fog, loss of headlights, heavy rain blocking cameras and driver's view thru the front windshield, etc. Try asking your dealer for an explanation and see what they come up with. As it is, eyesight along with Starlink, if subscribed, collect data and upload it for Subaru data mining for several reasons. Among them; collecting real time data for correlating and tweaking software to improve car electronics, providing data to insurance companies to help with their actuarial tables in determining insurance rates, and more. Here's a recent post;
https://www.subaruxvforum.com/threads/high-technology-reports-to-insurance-co-driving-habits.188227/
My new Xtrek Sport Eyesight took a brief vacation last year for a few blocks. After reading posts, I determined morning humidity in summer heat temporarily fogged the lenses until I turned on defrost on medium speed to move air until Eyesight returned. Two occurrences from my guess, related to interior humidity, quickly returning after some air circulation. This past Sunday, returning home from snow squalls in upstate NY disabled Eyesight; possibly from whiteout conditions, view obscured from snow covering highway lane markers and right side solid line. Eyesight returned when the snow squall subsided. Slowing down didn't allow Eyesight return but safer driving prevailed in whiteout conditions.
Others may have experiences to contribute how Eyesight goes away and returns.