Coming out: I don't like Slack (+ 2 reasons why) - And you?

Yes, I don't like this tool.
It's fashionable, loved by engineers, it has cool features, cool ecosystem, but I hate it because it's non-productive for two reasons:

1) Synchronous written communications with 2+ persons always lead to mess. (even with two persons it's often a mess).
In Slack everybody talk and then you write things about something, and another person asks another question, and you post, and it's a non-sense. It happens all the time in Slack.

Let's be positive and suggest an improvement:
The day they add a notion of thread, I'll open champaign.

2) Searching relevant info in a Channels is like gold washing.
Channels are perfect on paper. But unfortunately, humans are not made of paper.
They talk too much, they like making fun of others, they like playing with GIF, they like debating with enthusiasm of topics they care about. Result: trying to get relevant info from a channel oblige you to do two things: follow conversations live (and stop working), browse discussions of the day (and scroll like you've never scrolled before, putting your fingers in danger), which is a very painful practice.
The worst/bonus is that people who spend their day checking channel consider that what is posted on the channel is a "shared information" and will then complain if someone else misses it (and sometimes point that they "don't know how to use Slack").

Let's be positive and suggest an improvement:
This one is hard. Have a "sum up view" filtering content based on relevancy. (then how to define what posts were relevant?)
Have an artificial intelligence summing up discussions.

Bonus: When I send an email I flag it to remember it and potentially ping the targeted audience again.
In Slack, it doesn't exist. Worst, conversations disappear for some reasons after some inactivity.
Improvement: have a notion of flagging cross-coversation (not like the pin, siloed by conversations)

Result: the time spent/value obtained is the worst of all solutions I use for work.
I still like it. It's fun and fresh but it's not productive.
I'd love to improve if you have suggestions.