Why would I tie up $1,200 upfront in a device that’s going to be obsolete in a couple of years when I can spread the cost over time, preserve cash flow, and (if it’s a legitimate business expense) deduct the lease payments?
Keeping $1,200 in my business earning a return is often worth more than prepaying for a depreciating asset.
People happily lease $80,000 vehicles for exactly these reasons. Applying the same logic to a $1,200 phone isn’t irrational, just the same financing decision at a much smaller scale.