https://tidesandcurrents.noaa.gov/sltrends/sltrends_station.... shows the relative sea level trend for Boston. Eyeballing it, looks like a 10 cm rise in the last 20 years, with no sign of slowing down.

That alone suggests another 40 cm by the end of the century.

Why do you think the predictions are wrong?

I don't think the predictions are wrong. I think the rhetoric is hyperbolic.

Then perhaps I misunderstood.

Michael E. Mann wrote "Dire Predictions: Understanding Global Warming". He lives in Amherst, at about 90 m elevation.

The "the actuality of sea level changes where they live" is zero for him, as there is no sea where he lives, and it would take a very large increase for it to reach him.

How is that data point relevant?