The design of 7-seater SUVs typically features two side doors for the first and second rows, with access to the third row through a rear door or tailgate. The decision to have a single door for the third row is often based on structural considerations, cost efficiency, and space utilization.
Having individual side doors for each row could complicate the vehicle's structure, impact safety standards, and increase manufacturing costs. Additionally, it might reduce the available interior space for passengers or cargo.
While the standard design is prevalent, automotive manufacturers are always exploring new concepts and designs. Specific models and features can vary, so it's advisable to check with manufacturers for the latest offerings if you're looking for a particular door configuration. As of my last knowledge update in January 2022, I'm not aware of any mainstream 7-seater SUV with a 6+1 door layout. Always check with the latest information from manufacturers for the most up-to-date details on vehicle designs.