According to your needs, I can recommend the Multi-Region over Single Region, here’s why:

• Multi-region can be future proof specially if you are expanding your customer globally, this has more flexibility and scalability.

• If you have a global customer the latency can be reduced depending on the location and the location of GCP services near them.

• In case of unforeseen events in such a location, since data is replicated across multiple regions, recovery is not a problem.

• The only cons I can think of is the cost but it is worthwhile for a company that is steadily growing.

But if you choose Single Region:

• Lower latency if you have a specific region that is near the location for the app.

• Performance will be at peak since it’s a specific region/location for your app.

• The cost is lower.

• Cons, availability on different locations will be limited.