But what if that vendor product B got crippled (like recently Unity and today JIRA) for most of features that people deemed essential, or even vanished? People

But what if that vendor product B got crippled (like recently Unity and today JIRA) for most of features that people deemed essential, or even vanished? People who is less fortunate has to switch to more cost-effective solutions (it may include F(L)OSS ones).