Hi,
I would be after a LEGO Technics set which could be reassembled into many different things.
Had a look at lego.com and the closest thing looks like https://www.lego.com/en-au/product/liebherr-r-9800-excavator…
Last I played with Technics was 30 years ago :D and things have changed a bit .. like the wireless motor control …
That being said, I find many of the Technics kits to have a single large purpose-specific plastic which is just not so reuse-friendly.
Have you come across a Lego Technics set which made you think "oh wow I could build so many different things out of this" ?
Nope. They are generally designed for one model and may have an alternate build model but usually only Max 2
Any other variation models may be community driven (e.g. they turned the Porsche 911 RSR into an F1 car)