Based on the provided reference, the exact answer is that Batman cannot reliably defeat everyone.
While it is stated that He could beat anyone, this potential does not translate into a guaranteed outcome every time. The reference explicitly clarifies that that doesn't actually mean he always reliably will.
Reliability and Limitations
Batman's strategy often relies on "prep time" – advance planning and preparation tailored to a specific opponent. However, the reference notes a significant limitation in this approach: There's quite a few times where the plans he made during 'prep time' end up failing. This indicates that even with preparation, success is not assured against every foe.
The Context of Prep Time
Furthermore, the reference puts the effectiveness of "prep time" into perspective. It suggests that this ability isn't unique to Batman's exceptional skill level, stating that almost any semi-competent hero would be able to defeat anyone else with infinite prep-time. This implies that while prep time is a significant factor in Batman's potential victories, it is a general strategic advantage available to others, rather than a power exclusive to him that guarantees universal triumph.
In summary, while Batman possesses the capability and strategic mind to potentially defeat a vast array of opponents, the notion that he can defeat everyone reliably or consistently is contradicted by the fact that his carefully made plans can and do fail.
