This has had me looking into shell scripts on the forum and the battery-saver app from open-store.
I'm looking for something light that would just disable all these features without going into each option and then restore everything back as I had it.

To me this seems like something that should be included into a toggle on the Battery pull-down menu itself, much like most modern devices have a "low power mode".
How feasible would a toggle option to disable all these power hungry features and set the radio to the most energy efficient available in your location. Then toggling back would restore what you had previous. It seems like something the OS should provide and not additional apps.

Is this something people would want to use from the OS itself rather than additional possibly more flexible unconfined apps?

I would say being part of the OS leaves scope for more battery saving options if it was to be taken further as the OS matures, maybe scheduler tweaks or manual display brightness settings for example. But keeping everything a simple toggle for the UX.