When it comes to shooter franchises, there are two ways in which developers are able to keep things fresh. The one more commonly chosen in recent years is to provide a change of scenery through moving the series to a different time period.
The path less travelled is to provide significant updates to mechanics and gameplay, but that is the route that the Sniper Elite series has taken, and Sniper Elite 4 is no exception. There's always been something voyeuristic about sniping in video games.
With a powerful rifle in hand, you're perched in some bombed-out tower overlooking a Nazi-occupied town, your crosshairs fixated squarely on the head of an enemy soldier as he strides along his designated patrol route. He has no idea that with one pull of the trigger, you're about to send a bullet careening through flesh and bone, snuffing out his young life in a single, glory instant.
According to gamerant many studios try not to change a game's formula too much, given the risk involved and the potential to alienate a series' audience, but it's certainly worked in the favor of the Sniper Elite series. Over time, the rigidity of the franchise has loosened somewhat, with one of the largest steps being made for Sniper Elite 3 through an increase in the open nature of the game, and these improvements have followed on to Sniper Elite 4.
Sniper Elite 4's missions and mechanics actually are robust enough to back up that claim. Picking apart the Nazi war machine piece by piece, using whatever plan comes to mind, is a blast. The way it encourages you to stay mindful, experiment, and get better is a refreshing vote of confidence.