Clever use of every inch in this unusual shaped space and the use of wood counters makes every inch count as versatile and functional.
Not everyone can accommodate an kitchen island large enough for a small dance floor or sixty linear feet of perimeter cabinets. If space is a premium, it's obvious that all the area available has to be utilized completely. In that situation the use of multiple countertop materials may not be either practical or even desirable from a design standpoint.
Granite and other stones aren't suitable for food prep that involves direct chopping. They dull knives almost instantly in addition to being damaged in the process. Synthetic materials have some of the same issues. Wood is user friendly in so many ways. If the correct sealer is used it can be used for chopping, rolling dough and every other kitchen chore in the book.