Mt. Wachusett is like almost exactly halfway between Boston and Albany.

Edit: Northfield mountain is closer to the actual midpoint if your Albany friend is worried about driving further than you do. But honestly Albany friend would have a very scenic drive(compared to the ugly Boston one) if they took Taconic Trail/Mohawk Trail/Route 2A/Route 122 so I think it could make up for the extra distance if they're into nature stuff.

That is objectively false.

You're right, it's 20 miles away from the exact midpoint. The actual midpoint is by Quabbin.

It's pretty close though.

but not so much by driving time.

Mt. Holyhoke State Park.

it is about 90 minutes driving from both Albany and Boston, and has some great hikes and views and a nature center.

Mount Tom

Yup. Holyoke Range State Park. Seven sisters is a great hike.

Mount Tom in Holyoke/East Hampton or the 7 Sisters in Amherst (Maybe Hadley? I’m new to the area). Or make a trip to The Berkshires! They’re significantly closer to Albany but offer an amazing selection of trails of all difficulties, plus you get to kick it in a cute hippy town like Great Barrington or something a little classier like Lennox. Northern Berkshires has Mount Greylock in North Adams and Southern Berkshires has Mount Washington (both high level hikes with some tricky spots). Or you could do Monument Mountain in Great Barrington. That has a few trails on it. Well displayed with many levels of difficulty. All of the fore mentioned offer amazing views at the summit. Plus you will find wonderful restaurants all though out the Berkshires. Have fun & stay hydrated

Pioneer valley area, Northampton and environs

https://westernmasshilltownhikers.com/

It's a 50 mile drive from Boston and a 150 mile drive from Albany, but naw, keep telling yourself you're right.