All points aligned with conventional wisdom, IMHO, bar one: that it's easier to sell cost savings than revenue gains. Revenue gains can be quantified accurately, because revenue is recorded in all businesses. Cost savings, especially for staff time, can be much harder to measure.
I think for startups, trying to show growth, savings are less valuable then revenue growth. For mature businesses measuring profit, a dollar of cost savings is worth more than a dollar of revenue.
Agreed, mature markets have usually been carved up, and competitors have to fight to gain even an inch of market share. In such a scenario, a dollar saved is a full dollar in the pocket.
A dollar gained would have many costs to gain that dollar.