[burntoutfire]

You're comparing apples to oranges - your non-web dev examples have high impact while your web developer is doing something less consequential. In reality, you can have high impact as a web dev as well - say noticing and fixing a large security bug which could be used to steal personal data of a billion people - or improving performance of a popular webapp (say Facebook's main page), which can result in large amounts of electricity saved every year. These accomplishments are probably as rare as the non-webdev examples you gave though. In reality, as a data scientist or an embedded engineer you'll also most likely to be working on an inconsequential detail of some inconsequential (or straight up BS) project. The engineering field is very detail-oriented and it just needs a hundred peons for every "cool job", regardless of the subfield.