A good medium level U lock is designed to protect your bicycle, gate or equipment where only a solid medium level security is required. For instance, you are not leaving a ten thousand dollar e-bike for 2 weeks at the train station bike rack but just want make sure your regular ride to school is still there when you want to get home.
Don't be fooled, these locks are tough and to be defeated they require time, serious tools and ideal conditions. (no, a vise in a workshop with plenty time and no getting caught risk is not real life)
Medium level is sensible security for low to medium value property