Why I can't use packs other than 1.11.1 or 1.11.0 on CubeIDE 1.6.1?

[dungeonlords789]

..

[Cartu38 OpenDev]

You can't because some highly coupled link between FW pack version and related Device Configuration Tool (aka. STM32CubeMX) internal database.

Device Configuration Tool is promoting code generation based on FW packs API. At a point if some API break or ... you may face trouble.

Preventing pain, new project creation is always sticked to most up to date drivers (and minor updates of if any) ...

If existing project for sure STM32Cube ecosystem still allow you to use material you've. You may just be prompted about migration to latest you're free to accept or not then.

Being "forced" to get most up to date materiel maybe a pain but on the other hand is preventing you to face known already bugs ... pro & cons.

[Cartu38 OpenDev]

Such said if relying on STM32CubeMX tool itself you can select drivers version you want ... but at your own risk.