I think you've already listed a benefit, which is faster form completion. The average form asking for an address is usually in this order (assuming US address):
- Street Address 1
- Street Address 2
- ZIP Code
This is the normal way mail or packages are addressed, and often times the way a person usually reads or gives out an address verbally. This is drastically different; however, from what carriers actually do. Take for example, USPS (https://about.usps.com/publications/pub100/pub100_078.htm), they sort mail in the exact opposite order of the list above. In other words, they initially sort mail by ZIP code, and then ultimately use the street address to deliver it.
Here's some advantages and disadvantages to asking for the information in reverse order.
- In most cases a ZIP code can map to a unique City, or at the very least State, this means your app or service can autofill at least one if not two fields, which reduces user effort
- A bonus of the point above is you can reduce user error along with user effort. If your service or app can at the very least recommend the City and State (even if it lets the user change it), chances of typos or spelling errors are greatly reduced.
- The biggest disadvantage is like I mentioned above, it's not normal to ask for ZIP code first when entering a complete address. This uncommon ordering could cause users to be initially confused.
Ultimately, you'll have to weigh the benefits and problems to determine if a streamlined form is better for your users, or if the risk in possibly confusing users (possibly losing conversions) is too great.