It depends on personal preferences. Some people might think Tokyo Ghoul is better for its original story and character development. Others might prefer Tokyo Ghoul:Re for its continuation and new plot twists.
The biggest distinction is that Tokyo Ghoul:re builds upon the foundation of Tokyo Ghoul and expands the world and lore. The character arcs evolve differently, and there are new challenges and conflicts. Both manga have their unique charm though.
It depends on your taste. Some people love the depth of the plot and the evolution of characters in Tokyo Ghoul:re manga, while others might find it a bit too dark or complex. But overall, it has its merits.
I think there are a specific number of volumes, but I'm not sure exactly. You might want to check reliable manga databases or fan forums for the precise count.
One of the main themes is identity. The characters, especially those who are half - ghouls, struggle with who they are. Another theme is survival in a world where ghouls and humans are in conflict.