OP, I'm not sure you understand risk management.
First, when considering a hazard, you need to clearly separate "likelihood" from "severity". Bundling everything into a single variable (e.g. chance of dying from COVID-19) is unhelpful. What about the chance of catching it and being ill for 2 weeks? This has a cost too, which needs assessing.
Second, when contemplating risk mitigation measures, you need to consider both cost (and feasibility) of implementation, and effectiveness.
Living in a perfect bubble till a vaccine is found would be effective in avoiding infection, but also costly and impractical to the point of being impossible.
However, with a decent workflow, sanitising your shopping isn't that hard (personally, we quarantine it for a few days in a corner of our garage, which happens to contain a spare fridge/freezer), and while not being 100% effective, does significantly reduce the risk of contamination. Just like washing your hands (Why do you think that's required? Yes the virus does live on surfaces), and practicing social distancing.
For some the extra cost may be small, and therefore worth it. For others (e.g. a healthy busy young adult, with not much spare cash, who lives alone in a tiny flat), the cost may be comparatively higher, and the overall risk smaller, so it may make sense to skip the extra safety measures.
Health and safety and, more generally, risk management are always a matter of context. One size does not fit all.