Yeah, but synchronizing time gets easier the bigger the accuracy window is, and approaches impossible the smaller. 2 seconds in well within NTP's wheelhouse on all but the most jittery and unusable networks.
We could actually run a generic clock synchronization protocol to synchronize clocks over a partially synchronous network. I guess paxos kind of builds that in, which adds to its complexity.
Safety in particular doesn't require any timing assumption.
(Note that messages can still be delayed arbitrarily in both protocols)
From the link; "The protocol runs sequentially in synchronized ‘epochs’ that are 2 seconds long. Every player starts in epoch 0 at the same time...."