Earlier quoted context omitted.
Indeed, the Windows app is horrid. One of our older workstations is a quad core i5 with 8GB, nothing special but no slouch either, and the Slack app completely chokes that machine. The employee has to run Slack on her iPhone to be able to get regular work done throughout the day. On our newer workstations it's not quite as bad but it's still noticeable. Our oldest in-service machine is a Core i7 laptop I use when I'm…
Out of interest, what's your concern with Skype? After a hiatus of ten years, I'm using it currently for a customer, and, maybe apart from cheesy emoticons and space inefficiency, so far it has worked well. Am I the only one to like a native (Linux) desktop client with notification integration etc. more than a bloated web/Electron app?
The only solution on Linux that implements audio, video and screen sharing is Sky (http://tel.red/), and it's incredibly flaky.