While not practical to actually do anything… could be quite phenomenal for teaching the basic entry levels of binary and logic. And quite possible to build on the Forge.
The Babbage machine that has been recreated is his difference engine, which is really a calculator because it does not have the feature necessary for any higher function, a conditional branch instruction. There is a project afoot to make his analytic engine, which does. It will be a massive effort. See Plan28.org
A lot of you are old enough to remember when we thought of logic gates just this way. I still design computer systems and write S/W but honestly couldn’t say I truly understand it as well because now we develop a system by using low level objects, algorithms and compiler functions written by others. At some level the computers are already writing their own code. Can you say SkyNet?
The numerous steps between a programmer and computer code is why nowadays so many people find FPGAs hard to code for. But even those have quite a few IDEs which bring them up to the normal programming level, just with some restrictions on functions available.