The reality is build time checking for safety isn't as safe as it sounds, as others have mentioned. Not only are malicious devs a problem, but hardware fails too.
Build time safety checking is valid and useful primarily for developer productivity. Runtime checks which reinforce those (and other) constructs are for ensuring things proceed as intended. There is no contradiction. Your problem is many very useful developers prefer not to have all the build time checks, and you're not going to change their minds!
Technology adoption almost always proceeds faster in cases where the existing work can be carried over as much as possible. I often wish this wasn't the case, but pragmatically it is. To get to a safer world we cannot require rebuilding it from scratch.