Tax season breaks on the chase for documents, not on the returns
The workflows that strain an accounting firm sit between the client and the work, and rented software treats them as an afterthought.
Chasing client documents is the obvious one. A portal can collect files, but it rarely knows that this client's return is waiting on a partnership statement that has not arrived, so the reminder goes out generic or not at all.
Tax season capacity is the second. In the busy months you need to know which returns are ready to work, which are stuck, and who is overloaded, and that picture usually lives in a partner's head or on a whiteboard.
Engagement tracking is the third. Scope, fee, signed letter, prior-year notes and open questions sit in different tools, so a staff accountant has to go looking before they can start a file.
Each of these tools does its own job well. Each was also built for a broad market of firms, which means it was not built around the order in which yours moves work from intake to preparation to review.