That's my thought.You are ignoring serious cases. Yes a couple of thousand cases per week sounds bad but just 22 people are currently serious. Something is working?
Also something I'm wondering is that t-cell memory gives some immunity, but it sounds like it doesn't prevent you from getting a virus. From what I'm understanding is that it will prevent you from getting the more serious side effects. So if you have t-cells you'll likely get either mild symptoms or be asymptomatic. Which means it will spread, but it won't cause major issues.