I think this fills a different role.
“Forget about this thing completely till next week, follow up once”
vs
“This thing is important to me”
That said I would love to see bookmarks become more useful, personally I simply never use bookmarks (I also don’t use star in GMail), its basically a pointless button in the UX I have I never press.
With the topic reminder I am assigning deliberate work to the computer … activate stop watch … tell me about this again in N minutes. That allows me to dump stuff off my brain stack.
Slack’s take on this is this function it exposes on in the ... menu:
