I do like the continental championships, but I wish the WC qualifying was more of a global event. Then you wouldn't need this dipshit finals format now, and the entire qualifying process would allow for meaningful international competition during the entire cycle.
So you keep the World Cup every 4 years, and lets call that Year 0. In Year 2 you have the continental championships.
Year 1 and Year 3 are World Cup qualifying tournaments.
Spring of Year 1, you do as many 2 leg home and homes (using FIFA rankings) as you need to get down to 150 teams. So #150 vs. #151, #149 vs. #152, and so on up to however many FIFA members as you have.
Once that gets you down to 150, you get 30 groups of 5, determined by FIFA rankings, the highest ranked team hosts each group in Summer of Year 1, with a full round robin. All 60 1st and 2nd place teams advance.
Then in Summer of Year 3, those 60 teams are divided into 12 groups of 5, for another full round robin. Top 2 in each group qualify. The 12 3rd place finishers are entered into home and homes, which take place in the Spring of Year 0, for the final 8 spots.
You make the qualifying tournaments an event, I think that trumps adding teams to a dumb format to get to 48 in the "final"