It's worth being concrete about what "discovery" actually produces, because the word gets used loosely. Here's the sequence, in order, and why each step depends on the one before it.
First, a facilitated workshop — the actual conversation, with the right stakeholders in the room. Second, a structured questionnaire that captures what the workshop conversation surfaced, in a form that can be scored rather than just remembered. Third, analysis: a first pass at scoring and summarizing, done quickly precisely because steps one and two gave it structured input to work with. Fourth, an executive report — the maturity score, the gaps, the recommendations, written for a decision-maker, not a technical audience. Fifth, a proposal and statement of work, if the organization wants to move forward.
The order matters because each step is cheap if the previous one was done properly, and expensive if it wasn't. Try to skip the workshop and jump to a proposal, and you'll write a generic one. Try to skip the questionnaire and go straight to analysis, and you'll be summarizing your own assumptions instead of what was actually said.
Discovery isn't slow because five steps is a lot of steps. It's slow when each step has to happen from scratch, with no structure carried from the last one. That's the thing worth fixing.