A single account consumes three distinct kinds of time: mechanical work in the platform, judgment work deciding what to change, and relational work explaining it to a client. The first scales beautifully — tooling has crushed it. The second scales poorly. The third does not scale at all.
Past roughly eight accounts, the judgment work is what fails first, and it fails invisibly. Nobody misses a deadline. Campaigns keep running. What disappears is the weekly moment where someone looks at an account and thinks about it rather than processing it.
You detect it in the reporting. Narratives get shorter and more generic. "Continued optimization" starts appearing. Clients stop asking questions because the answers stopped being interesting, and eight months later one of them leaves for reasons nobody can name.
The practical fix is not a better tool or a longer day. It is separating the three kinds of time and only keeping the one you are irreplaceable for — which for most agency owners is the relational work, not the platform work.