Helmet and eye protection is what you wear on a regular e-scooter or bike. You wear motorcycle gear if “keeping up with cars” is a meaningful concept for your vehicle.
You can die from getting hit by a car while stopped at a light. People wear helmets on low speed vehicles either because their personal risk assessment or the law convinces them.
I don't know about where you live but where I'm at, no adult wears a helmet on a <20mph escooter.
I said wear a helmet and eye pro because at 25-35mph and above the wind is so strong you can't keep your eyes open and clear without it, hahaha
Where I live, e-scooters have a speed limit of 25 km/h (15.5 mph). Any faster and it needs to be registered as a motorbike, where a helmet is mandatory. Some people take the risk and ride unregistered fast e-scooters, but they’re surprisingly aware of the danger and usually wear full moto gear.