Acela trains share track with freight, TGV and ICE certainly don't. This includes the requirement for safe collision with a freight train, which adds a lot of weight.

The ICE shares tracks with freight trains as well. Only the TGV has completely dedicated tracks afaik.

Thanks for the correction; ICE trainsets are still way lighter right?

Depends.. ICE1 trainsets appear to be slightly heavier than the Acela, whereas the newer ones are lighter. But that seems to be mainly due to having no dedicated power cars (ICE1 and the Acela Express do have power cars).