How is it impossible? Plenty of studios will work on multiple projects. They can easily have multiple teams working on different projects under the same studio. To think that a company as large as Bethesda is only working on a single IP at any given time is idiotic.
Because their scope is bigger than anything else. If they did what you wanted and worked on all their IP at once, you’d hate it because it wouldn’t in any way resemble a Bethesda game. It takes their whole studio committed completely to it for half a decade for their games to exist.
They absolutely are only actively developing one game a time. They might have a handful of teams that don’t have a specific project for the game they’re actively developing doing rough broad strokes on the next project, but that next project absolutely isn’t being developed.
