PFS will make it so connections need to be individually attacked but since most PFS is done with Diffie-Hellman variants (susceptible to Shor's algorithm), the group size also needs to be large enough to resist early quantum computers.
For defense against large quantum computers, different PFS schemes need to be used (fortunately not hard to construct from other post quantum primitives).
For defense against large quantum computers, different PFS schemes need to be used (fortunately not hard to construct from other post quantum primitives).