What’s an obvious software product that could be 10x better if approached fresh and with craft?

e.g., what Linear did for software development or Slack once did for office messaging

Anki. Amazing tool, obviously works, just needs a better UI 

https://senrigan.io/blog/chasing-10x-leveraging-a-poor-memory-in-software-engineering/

Exec Program is essentially Anki for programming with better UI: https://www.executeprogram.com/

The only qualifier is that creating the cards is a valuable part of the Anki philosophy