Is the Dominion the most powerful civilization in the Milky Way currently?

After the events of VOY and the aftermath we've seen in DISCO and PICARD, the Borg collective is but a shadow of its former self... with them effectively out of the picture, does that mean the most powerful space-faring civilization in the Milky Way is now the Dominion?

Also, with the current state of the Borg, could the Dominion theoretically expand its borders into the Delta Quadrant? I would imagine that any civilization strong enough to even stand a chance at repelling them would've already been wiped out long ago by the Borg, no?