Thanks for reaching out to the Community, Chiranth.
I can certainly understand how an ability to create users who only have access to view invoices/download their attachments could be useful and have submitted a suggestion about it as of today.
You can also submit your own feature requests while signed in.
Here's how:
- Use the Gear (⚙️) icon.

- Choose Feedback.

- Enter your suggestions and/or comments.
- Hit Next.

- Click Skip and send message.
- The available drop-down menu can be used to pick an appropriate category.
- Select Send message.

Your feedback's definitely valuable to Intuit. It will be reviewed by our Product Development team and considered in future updates. You can stay up-to-date with the latest news about your product by reviewing Intuit's Product Updates webpage.
Please don't hesitate to send a reply if there's any questions. Have a great day!