If your company has been trusting ad dollars to agencies you are very familiar with the concerns: are they using my data responsibly? Are they moving fast? Are we creating too much dependency on them? What happens if they are going out of business?
Because of these fears, companies decide to take the media team back home. They hire media analysts, engineers, and form a new ad division. Suddenly, managing their own in-house team becomes a bigger hassle than managing agencies.
I understand there is a risk on partnering with companies that are too close to your revenue. There is a market reality here: because technology has moved so fast, it is doubtful that your in-house team will catch up. The ones that are moving more quickly are those companies specialized in one single problem: user identity, cross-channel tracking, channel-specific optimizations, data visualization, etc.
Have your own in-house, yes, but don’t make them compete with the agencies, allow them to understand the big picture and act as auditors.