If you maximize seat safety, you minimize the number of seats you have because you bunch up all your voters. This means that the opposition need only flip a few districts to win back a majority (and then redistrict to their liking!).
If you maximize the number of seats you have then you spread your voters thin. This makes it easier to win in a wave: with many districts close to 50/50, you only have to flip a few percent of the voters state-wide or nation-wide and you win. And that's exactly what's been happening. We've had a number of wave elections recently.
If you maximize seat safety, you minimize the number of seats you have because you bunch up all your voters. This means that the opposition need only flip a few districts to win back a majority (and then redistrict to their liking!).
If you maximize the number of seats you have then you spread your voters thin. This makes it easier to win in a wave: with many districts close to 50/50, you only have to flip a few percent of the voters state-wide or nation-wide and you win. And that's exactly what's been happening. We've had a number of wave elections recently.