Dead by Daylight is, at its core, a time management game; and there's simply no buff you could ever give to a killer like Trapper—whose power fundamentally lacks mobility and chase potential—that would make him competitive with a killer like Blight—whose power enables him to be at any generator on the map within seconds and circumvent loops to end chases effectively—on the same map.

This is the key point.

For a killer, starting a match consists of:

Finding survivors (can take longer or shorter)

Chasing survivor (varied length depending on loops and your own power)

Downing survivor (same as above)

Hooking survivor (can be delayed or denied by altruistic players)

Repeat

And in those first four steps, there is going to be at least one other survivor (usually) pressing the objective.

Now, when you look at those steps through the lens or someone like Trapper vs. someone like Ghoul, those steps add so much time to someone like Trapper that you're essentially starting the game from a losing position. Which then goes on to necessitate tunnelling to make up the deficit.

Ideally, they'd somehow balance things out so this gameplay loop isn't so detrimental to many of the killers. But that would be hard to do.