I guess I might be in the minority liking how they are doing the time jumps. I think they are doing the best they can with showing key moments in the years leading up to the war without adding too much filler that will slow down the action. I do think the show would get complaints about very little happening if they spent more time fleshing out relationships with characters who end up being long dead before the war starts. Those characters are footnotes in history, but we just needed to know who they were.
If they had started the show around the start of the war, it would be so hard for audience to understand everyone’s previous marriages, interactions and who has what children, so I think the times jumps are the best compromise to explain without dwelling too long on set-up.