This is a tough one. Gig workers often bring their own tools, unless those tools are company specific. I've worked with lots of musicians who are contractors. They show to a location with their own music gear. And this is clearly understood.
While I think arming regular drivers with PPE at no cost would be good for publicity and morale, the demand for PPE is not much different than expecting Lyft to fix drivers' cars.
Hand sanitizer for riders? Yes, that should be provided. But a mask for the driver? No. But Lyft would come out ahead if it sent out logo masks. That's advertising.
But, I digress...
I've been a self-employeed contractor for decades. The only tools clients provide me are proprietary ones (e.g. paid user access to the company's task system).