Anyone here deal with security questionnaires regularly? Looking for real feedback

I’m building a tool to help B2B SaaS teams answer security questionnaires faster (the ones that slow down deals).
If you’ve ever had to fill them out (or help your company with them), I’d love honest input:
How many do you usually get per month?
How long does each one typically take?
Do you use any tool for this right now (Loopio, Responsive, Conveyor, Vanta, etc.)?
If yes — how useful has it actually been in practice?
What’s still frustrating or missing?
Not pitching anything. Just trying to understand if this is still a real pain and where current tools fall short.
Thanks to anyone who shares their experience.