In england it also works like that (and most other countries) if 1 party doesn’t get over 50percent of the vote a coalition has to be made which will then be over 50 percent.
In 1974 the party without the popular vote, got more seats in Parliament, and became Prime Minister.
It was so untenable, that within a few months, a new election was called. But someone can become the British Prime Minister even without 50% of the popular vote, as long as s/he has over 50% of the seats in Parliament.
Meanwhile, both Lapid & Bennett better begin fearing for their Olom haBo, let alone for what might transpire in the next Knesset election.