What are the biggest pain points of running a solo business today?

I'm building RunoSO for freelancers and solo founders, and I've noticed that everyone seems to have a different workflow.

Some people use Notion, some rely on Google Sheets, while others have separate tools for invoicing, passwords, and project management.

If you're running a solo business today:

• What's the biggest operational headache?

• Which tools do you switch between most?

• If one tool could solve one problem perfectly, what would it be?

I'd love to learn from how everyone here works.