I have to stress once again, for what's probably the millionth time, that the whole "Whoever isn't in your party will die at the end of Act 1" is not just terrible as a narrative device, but arguably even worse as a mechanical one.
And if it wasn't just bad in itself (which, just to be clear, it totally IS) it becomes downright atrocious when tied with the decision of limiting the party to four characters (under the assumption that your audience is made by smooth-brained people who can't keep up with the complexity of having more).
I mean, we agree on not killing the party, but by Avernus: you really need to open a window and get some fresh air.
I always thought you were somewhat versed in 5e mechanics, so it cannot be a suprise to you that a 5e game takes the recommended party size in account. Which, in pretty much every source material, is 3-5 players if not outright 4 players. Out of the box 5e is adjusted for 4 PCs, so it is only rational to take that number.
So maybe calm down on the rethoric a little bit.
