We are at the limit of helmet design assuming the shell is the ideal balance of carbon, kevlar etc (likely from Senna's accident!) and the foam is ConFor which is the best energy absorber as long as temperatures are above about 12oC (likely sat on someones noggin).
So the most likely change, long suggested & long discounted, is to "F111 bubble the cockpits". However that reduces one injury risk (debris & car in the face re open wheel contact stacking cars), but you potentially introduce a significant thermal load on the driver for the race which increases other risks. Most closed-cockpit "World Cars" have serious heat exhaustion problems despite a silicone hose as big as a dryer's stuffed right in front of the driver's face.
Whilst the driver did not steer, I think he did brake - the tyres can be seen momentarily stopping & restarting as ABS kicked in on the runoff area. It may be he couldn't brake effectively or simply had his foot on the brake pedal and engine braking deceleration in an F1 car is enough to push the pedal. Gravel traps are a problem if you hit them sideways (which is very likely in a tail-heavy F1 car) because they will induce a barrel roll. Humans will tolerate 120G+ in a full 6pt harness, 40-55G in a conventional safety belt, but just 10-15G in a vertical impact. That tyre wall was a lot better in depth than those about 20yrs ago and was hit head-on with alloy or kevlar honeycomb front crush-box of an F1 car. Kevlar crumples from the point of impact unlike steel which crumples less predictably some distance behind greatly increasing the risk of entrapment. It appears the damage sustained by the driver was, essentially, from road debris.
World Sports Cars can have their moments, re Mercedes airborne takeoff flip many years back. Motor Racing is vastly safer than it was, deaths were not just routine but expected throughout the season.