As with debugging, it's important to choose your battles. How often do you start up slack? Is that 45sec once per day or even per hour, or is it per minute? Obviously it's not a frequent occurrence. So that delay, regardless of your computing power, is not an issue. A case where it does matter is with a good mobile phone camera. It must launch and be able to capture an image within one or two (or at least within 5) s…
I understand this argument for niche tools. I'm eternally grateful for things like Insomnia (a GraphQL client), NoSQLBooster (MongoDB GUI), etc, all written in Electron. I understand that asking for things like that in native is a recipe for them to not happen, or for them to be Mac-only, or for them to cost $100/year.
Slack is not in this category. It is produced by a corporation valued at three billion dollars. It is a product that is completely, totally, and wholly solved. They produce very little that is novel. I expect that experience to be all twenty shades of pixel perfect, because they have no excuses.
Let's look at Telegram. Great app. But they wondered if there were ways it could be improved, so they released, simultaneously, Telegram X on the app store [1]. A rewrite, using the same backend and APIs. It's even better. With Slack's resources, they could have done this twenty times over.