1. “enlist” implies “volunteer”. Most Israel youth are “conscripted”. The only time someone enlists is when they are exempt, such as the case with most Arabs who serve in the IDF.
2. The real number that matters is the extent those conscripted volunteer for combat units (e.g. Golani, Air Force, etc.), rather than aspire to be “jobniks”. If conscription was abolished (as virtually ever major democracy has done), it is reasonable to assume that those who choose to be in combat units would still “enlist” (and presumbably would be paid serious wages to do so). Also, a volunteer army would be forced to offer accommodation to frum soldiers to get them to sign up, rather than doing so begrudgingly as is the case today.
3. Israel does not allow conscientious objection (if so, non-zionist hareidim would be exempt) leading to the charade of liberal yeshiva deferments. This is also a problem for non-religious Jews who are also conscientious objectors who jump through hoops to avoid military service. Switching to a western-style professional army would solve the problem.