It’s already been said: FOSS projects can be abandoned, but resurrected via forks and re-writes, whereas proprietary apps are simply dead with no recourse unless the original dev/team releases the source code.

That being said, I am not a developer, so when a project dies, I am at the behest of other devs to revive the project. I do find that projects that many people value, like all the recent discord alternatives or health/money management apps, tend to survive longer because they provide value to a wide range of people. Things like wikis or new protocols are far more niche, so I am not surprised that they might not outlive projects like sharkord or rackula.