I'd sure hate to do general development without a legacy mouse. I actually do it quite a lot on my laptop and it is very tedious. Fairly impossible to replace the mouse with something as efficient for these types of use-cases.
Imagine using a desktop someday that'll recognize more than the singular hit area the mouse provides.
Once you go beyond more than two finger gestures (and for even stricter use-cases 3 fingers) this is basically useless imo. There is an example in compilers where we talk about running for optimal execution using a single program counter (finger). What happens when you have more than one finger? How do you do optimal execution? The more fingers you add, the harder the problem becomes. Similarly, in this case of using many fingers or many hit areas for input, what are the use-cases you can envision? IMO, it's really hard to come up with things that aren't going to be gimmicky and mostly useless.