Why did senzu beans become so scarce?

[SSJ2]

As recently as the Piccolo Daimao arc, it appeared as though there were over 1,000 senzu beans. Yet at a critical point in the series when the Saiyans arrived, Karin only had 2 that he could spare. So what happened to this enormous stash that he had?

 

[Alin]

Plot convenience.

 

[Hector]

Yadjirobe. That's what happened.

 

[Captain Cadaver]

Karin had probably been growing the senzu for centuries based on his age and that pot was all those centuries amounted to. It makes sense that only a few senzu can be grown annually and Yajirobe probably consumed centuries of hard work.

 

[Warmmedown]

https://www.plantbasednews.org/lifestyle/uk-vegan-population-will-skyrocket-by-327-by-2020-claims-poll