Router-to-L2 vs Router-to-L3

I’m probably overthinking this, but I am genuinely curious as to what advantage one scenario has over another. Granted it does depend on the gear you’re working with but let’s say both are L3 WAN switches…

Scenario 1: Nat router connects to a switchport with an SVI gateway living on the switch.

Scenario 2: Nat router connects to a routed port as its gateway in a /30 subnet.

Both get the networks behind the nat router out to the Internet, but what’s the rhyme or reason for doing one over the other?

This doesn’t exclusively apply to WANs, but this is a scenario I’ve run into recently.