It’s endemic now, meaning that due to a number of factors (including that it is dormant in wild animals), it will exist forever at some baseline.

This is analogous to how HIV is endemic and kills ~1M per year worldwide.

Yes, and we are all going to die.

I think once vaccine rollout was widespread it was time to lift many of the restrictions. But regardless of your opinions on this, MIT is not claiming the restrictions are still there because of COVID. They are outright saying they are keeping the closed campus as other restrictions are lifted, for security reasons.