My problem with the app isn't resource usage, it's that a chat client that's already a webpage shouldn't need me to install a app. It's ridiculous how far slack will go on purpose to not support the platform their app is built on.
As a chat client that facilitates communication with my coworkers, I don't want to limit it to a tab in Chrome. Chrome is an app that I close often, I can't recall a time I've wanted to close Slack.
I never close my browser unless I have to, but sure that might not be the normal behavior. I still don't get why they can't give an acceptable experience on the platform they built it on without wrapping it in a useless wrapper.
Keep the app, just make sure I can use your service on the platform it's built on.
That's fine but they should make it possible to use it completely in-browser as well. I'm not a fan of having five Chromium instances constantly running on my MacBook.