In minecraft bedrock edition there are commands like /fill [pos1] [pos2] [Block you Want to Fill it With] [Optional: Mode] [Mode Arguments]
However, getting coordinates, writing them down on paper, ect takes a while, and I feel like for someone who knows how to do command blocks, it would be really easy to just make a tool that sets the positions and runs thhe command for you.
use tool to set 2 corner positions
then put in chat
/fill stone replace air
and you wouldn't have to put the position, you would just be able to do that and then all air will be replaced with stone.
Agreed, clone commands are nice but the game feels like a shell of its former self without the worldedit wand. That thing was sooooooo useful and I remember using it near a decade ago. Why have these ideas not been implemented into the game yet? It makes no sense at all.
Runecraft was another great mod that could have been implemented into the game.