The advantage of having your L3 switch directly connected to the router, it avoids L2 switch processing latency (generally very minimal) and L2 switch congestion issues, both latency and drops. The latter can be significant, or not. I.e., without knowing much more about your topology and hosts, 4 L2 switches between your L3 switch and router, might not be an issue, or could be a major issue (as could one L2 switch between your L3 switch and router).

PS:

If the router in question connects to WAN, often the WAN link is more of a concern than LAN L2 topologoy.