It's basically never worth replacing the old stuff. Only adopt new stuff if the future use cases are so huge (10x the old system) that the old stuff becomes a s

It's basically never worth replacing the old stuff. Only adopt new stuff if the future use cases are so huge (10x the old system) that the old stuff becomes a small afterthought that you can easily afford to throw it away (and lose its value) or pay the cost of rewriting it (which mostly cancels out it's value)