That's exactly what L2 is. Otherwise the orbits of JWST and Earth would have different periods. It's handy to be able to have constant high speed communications and not need large antennas with blackouts.
It also is handy to keep the closest IR sources (Earth and moon) in the same direction as the sun at all times so there is never a point where you have a significant IR source above the sun shield.
Re:James Webb is fully deployed
by moffkalast on Sunday January 09, 2022 @11:36AM
(#29864786)
Ah yes I hadn't considered the IR sources aspect, that makes a lot of sense.
I guess it gives you a very stable position for observations, but why not just put it in solar orbit then? Then again this is kind of a solar orbit that happens to stay close to the Earth at all times so that's a plus for comms.