Look at their respective wage bills and look at their respective spend.
Leverkusen are a far better coached team than Bayern and that shouldn't be happening with their respective resources.
Wage bills/spend only work as a marker of success over a longer period. Any team can strike lucky and have an amazing team for a season or two.
What will happen is the stars will be picked up (Wirtz especially) and Alonso will be poached. But right here right now the stars have aligned and it’s an amazing side.