The IDF's "manpower shortage" is actually part of a political debate over the Haredim serving and more generally about load sharing within Israeli society.

It is true that one sector of society (the national religious 10-15% of population) bore a disproportionate amount of the combat casualties because their youth is most motivated to join combat units and are a high percentage of combat soldiers. They are also the most motivated reservists.

Secular people do serve in combat units but there was a skewing towards "safer" non-combat roles and particularly more lucrative (career wise) intelligence roles (ie 8200) that lead to high tech success.
It used to be the case that if you got both a top intellectual profile and physical profile you would go into intelligence, not combat. Now many are sent to combat.

If you look at the birthrates from 18 - 25 years ago you will see that there was a huge increase in Jewish births over this period and thus the IDF actually has far more potential recruits than ever before. This increase was partly Haredim but also more generally.

So there is no overall manpower shortage, indeed there is more manpower than ever before.
But these are definitely issues about correct balancing of combat vs non-combat forces (which is being addressed with new recruiting pushing more into combat) and the sharing of the load within Israeli society.