The first had a small team (< 5) of also highly paid senior developers like him to build and maintain a set of systems. I wouldn't call it "manage" so much as "

The first had a small team (< 5) of also highly paid senior developers like him to build and maintain a set of systems. I wouldn't call it "manage" so much as "coordinate colleagues". The second was working alone. In both cases the work was difficult to do, difficult to share across a team (solve a few hard problems well rather than cycle through hundreds of small JIRA tickets) and highly value adding for the company which is why they were willing to pay.