https://www.marinbikes.com/bikes/2021-san-rafael-ds1
https://www.specialized.com/us/en/si...=322026-200206
of the two I prefer the Specialized because it does Not have a suspension fork. Neither bike would be excellent on real mountain-bike trails but the shock is likely to be heavy and useless on the street and not much help for anything over two inches tall ... it only has 63 mm of max travel.
The Specialized has 8 rather than 7 cogs, hydro discs, a steel fork (a little heavy, but good shock absorption) and while I like Marin, in this specific comparison, I like the Specializd a little better. I epect it will be a little more durable just because the shock it doesn't have, won't need servicing. Simple is goo d in this case.
As others have said, neither will be light, or fast on or off pavement, but either could be a lot of fun