Client: I need a modification to this cabinet so I can put in a double stove.
Carpenter: Welp, we are gonna have to demolish the whole kitchen. So with the estimate of a full kitchen remodel you are looking at $80k
Client: ...
I guess my analogy is being scrutinized (so to speak), that being said; YES!, that WILL happen if the carpenter doesn't know any better (or is a crook).
A smart/savvy (or whatever you want to call it) carpenter will easily do the modification[S] without tearing down the entire kitchen. Just like you can drop React into an existing project.
Say clients wanted a kitchen completely remodeled, you still don't have to use hammer and nails or nail gun --- I could easily demolish the kitchen and 3D print the new kitchen
What you know/done before doesn't necessarily dictate what you'll [can] do (which is the case on the Web)