It's not 13 years of development, it's them being used in edh for 13 years. They got roughly a year of character development in recent various sets, then roughly cast aside as soon as the second set ends. And in a very real sense, this shows the downside of abandoning the block style of card production and marketing. As these stories are all just marketing pieces really, that's why they exist. And the speed of releases to meet the demands of Hasbro. They just do not have time in any particular set or couple of sets to do anything other than set up and payoff. First set, create the threat. Second set, it is resolved. Just for fun, the phyrexian invasion could've been strung across multiple card sets with each focusing on particular planes and praetors and their compleated walkers invading. Mirroring the build up we saw in other sets leading up to this one in Kakigawa, Kaldheim, Ikora, etc Especially against the walkers' home planes. Instead, they've all been smooshed into one big set where each world shattering invasion is lumped together and then defeated instantly. The speed at which they have to move onto the set after this demands that's what happens. There can be no down sets, they all must be equally big hits so this is how the story must be crafted going forwards. Huge threats built up then resolved almost immediately.