Bennet said that he won't join a government led by Lapid. This seems to put a lid on Lapid's ability to form a government, and is a big boost to Netanyahu (joining a Netanyahu government is an easier spin for Bennet with Sa'ar ending up at 13 seats).
However, imagine this situation: Likud + Haredim + Kahanists + Yamina can't reach 61, only Yesh Atid + New Hope + Yamina + YB + Labour + KL + outside support from Meretz can. What'll happen first- Bennet breaks his promise and sits in a Lapid government with Labour, Sa'ar breaks his promise and joins Netanyahu, or a new election? Hard to say, but I wouldn't completely discount the first.
Can you imagine if Lapid is forced to give up the Prime Ministership then? He’s been the leader of the second or third largest party for eight years now, and he still might not be able to succeed Netanyahu.