My dad grew up on a farm, and latter regretted not inventing the large round baler that most farmers use - he already knew about small round bales, so the only thing missing was make them larger and then haul them on a tractor instead of lifting by hand as you did the small bales. Despite saying the above for years it never occurred to him to invent the large square baler which the same concept (haul with a tractor), but stack better. Everything was known and so obvious in hindsight.
Often the obvious stuff was invented decades ago, but some old people in power persistently refuse to implement into major products. Like the ability to copy multiple things without overwriting the previous entry. Who would ever need that?!
