You're coupling anecdotes ("where I live"), hypotheticals ("perhaps the solution"), and confounding variables (improved overall vehicle safety isn't just due to vehicle size).

The evidence is clear. Increased pedestrian deaths are largely due to vehicle size.

Perhaps the underlying thought is there must be a way to make cars safer for passengers and pedestrians. One demonstrable way to achieve this is better infrastructure [1][2] rather than just building bigger cars.

[1] https://www.vox.com/23784549/pedestrian-deaths-traffic-safet... [2] https://www.strongtowns.org/