1. If we didn't lockdown - hospital system would have likely collapsed - more deaths illness in the system and secondary effects.
2. The rate of spread would have been faster and probably we would have seen variants get more traction.
3. Lockdowns bought us time to get vaccinations developed, manufactured and distributed and taking off some of the burden on our health care system for which we are only still paying the costs of (burn out for employees, delayed procedures etc).
These guys clearly have an agenda .. one of them works at the Cato Institute. The also released this under the brand of John Hopkins knowing full well it would get attention for its Health reputation but its John Hopkins economics. Slimy.