The UX you describe is one I haven't seen in Slack since very early releases.
https://slackhq.com/threaded-messaging-comes-to-slack-417ffb...
Threaded conversations have been supported for a full year now, you have the ability to specify and narrow your searches down to specific rooms by using "in:#general" or by conversation by using "in:@dave", but a plain search will search as best the application can public rooms, private rooms and private messages, and the application does a great job I think telling you exactly where the search results come from, when they happened along with a contextual view of the conversation that happened before and after the search results-giving you the precise context of what was talked about, and allow you to both jump back in time to the moment the keyword appears, and jump back to "Now" very easily.
https://slackhq.com/next-level-searching-in-slack-1ce56aa8ad...
Again, sorry if this sounds snarky, but I don't think your critiques are really lined up with how Slack has been developed in the last year. Many of your problems have been directly solved.
The fact at that slack has to blog about how to search proves my point, IMO. Gmail doesn't need a post about that. I'm talking about context, which is where search fails, because threads don't work. I can find keywords in slack just fine (which is all the blog post talks about, really). I can't find and save an entire conversation about something important.
:/ I've tried slack and all the shortcuts. It fails as a business tool. Simple email and chatting produces more productivity.
Speak for yourself. Our DevOps uses it extensively, and gets plenty of work done. It's been a great tool, has saved time, decreased ticket response time, and increased follow up. If we didn't have it, we would have to scramble to find something to replace it.
Slack now is a significantly improved tool that we use all the time for everything except large or external video chatting. It's a very nice tool for centralization of alerting, monitoring, etc. We'd find it very hard to move elsewhere as a company.
Try search for a conversation with someone in a channel about topic X. You can't do it, because there is no context. Search for the keyword or person? Good luck with that. Even then, if you find it, it just scrolls you to that spot, which is terrible UI.
Ugh.