Nextcloud does not let you skip major updates. I don’t know if it is possible with Softaculous to first install an image with NC 33 and then the latest one.
Between major upgrades, there can be breaking changes, so you can have different steps to be carried out at a given major upgrade. These procedures are tested, and it includes apps that need to update their code as well. If you start to skip major upgrades, you have to make sure that all the intermediate steps are carried out correctly, and that perhaps for different apps. To manage and test all of that is not trivial.