“Build vs buy” assumes that there are only two parties. If it’s easier to build internally, then it’s easier for a 3rd party competitor to enter the market and bid the price down. I think the "zone of viability" is real, it just narrows and shifts downward.

The author hints at this in a footnote: > It does, however, pencil out to use a different product instead. In this particular case, it’s easy: use Linear instead of Jira.