Although technically simpler than soft launching, its disadvantage is that the missile silo has to be more resilient to damage.
Soft launching has to overcome the difficulty of first expelling the projectile from the silo passively (without engine ignition).
Usually, soft launching requires two independent systems: one to expel the missile, and the second to ignite it after adequately clearing the silo.
If there is a malfunction, the missile can detonate inside the silo, severely damaging neighboring components and auxiliary systems of the launch base.
[4] The US Navy has been adopting more versatile launch systems that can work in either modes.