I would prefer to not use Salesforce until I have to - I know it's expensive, slow, and hard to customize. At the same SF users who I know tell me that nothing else works for orgs of above 100 people.
The demo looks great and I like that you are focusing on UX and performance - I would expect Linear-like experience for a tool I use every day. I would prefer a hosted version (my experience with self-hosted analytics/business tools was a nightmare).
At a certain stage of a company, sales reps expect Salesforce. So much so, that even when we finally caved and got it, I had reps specifically turn off Lightning and stick with Classic mode. It's like Bloomberg - it's what they know and can move fast in.
As much as it pains me to say this, it may make sense to have an option that can mirror the Salesforce UI vs reinventing the wheel. Or maybe even an integration / escape hatch to migrate everything off of Salesforce to this. Basically, if you want reps to adopt it, make it close as possible to what they know.