Drive is storage with sharing, and its sharing is organised around accounts and permissions.

This guide covers the three things that go wrong, and what to use for the recipients where they matter.
The permission screen
The default sharing setting is restricted. Sending a link without changing it produces a request-access screen for the recipient.
They then either request access, which arrives in your inbox at an unpredictable time, or they assume it was a mistake and reply asking.
Either way, the first thing they experienced was a barrier.
This is entirely avoidable and it keeps happening, because the setting is per-file and easy to forget under time pressure.
The download on a phone
Even with the setting correct, a document link opened on a phone opens in the Drive viewer or app rather than as a page.
The recipient now has a file in a downloads folder and needs an application that opens it. For a document format that is common; for anything less common it is a dead end.
Some recipients stop there, and they do not tell you.
| Drive link | Page at an address | |
|---|---|---|
| Permission screen | Often | No |
| Opens on a phone | In the Drive viewer or app | In the browser |
| Shows other files | Only if you share a folder | No |
| Needs an account | Sometimes | No |
| Good for colleagues | Yes | Yes |
| Opens as a plain page | No | Yes |
The folder structure
A Drive address is a location in your drive.
If you share a folder rather than a file, the recipient sees everything in it. Including the things you forgot were in it.
Sharing a folder with a client is an easy way for internal material to reach an outside party, and it may not be noticed for a long time.
Never share a folder outside the organisation. Share a file, or better, publish what they need.
What to use instead
For anything a client is going to read, publish it at an address.
They tap and see it, on whatever they are holding, with no account and no download. The address says nothing about your files. And you can replace what sits behind it when the document changes.
That covers proposals, reports, quotes, brochures, price lists and most of what actually gets sent to clients.

Keep Drive for what it is good at
None of this is an argument for abandoning it.
Storage, version history, working files, collaboration with colleagues who have accounts. All of that is what Drive is built for and it does it well.
The change is narrow: stop using it as the delivery mechanism for people outside the organisation.
Test in a private window
Whatever you send, open it in a private browsing window before sending.
Your own session hides every permission problem, because you have access to everything. A private window shows you what the recipient will see, and it takes ten seconds.
This single habit catches many sharing mistakes before they reach a client.
Closely related: How to share a file without making anyone log in, and File sharing website or a link to a page for the adjacent problem.
Put it at an address
Keep Drive for storage and colleagues, publish at an address for anything a client reads, never share a folder outside, and test every link in a private window.
Then the client sees the document rather than a permission screen.