I would posit that learning how the device works, and how to integrate with a newer digital monitoring device would be just as interesting and less brittle.
Possibly! But I’ve recently wanted to dabble with computer vision, so I’d be looking at a project like this as a way to scratch a specific itch. Again, not OP so I don’t know what their priorities are, but just offering one angle for why one might choose a less “optimal” approach.
Happiness for me is about exploring the problem within constraints and the satisfaction of building the solution. Brittleness is often of less concern than the fun factor.
And some kinds of brittleness can be managed/solved, which adds to the fun.