If you want to construct a mathematical curve, you can construct it out of sums of other curves or can go to segments called splines. Splines (or segments) have been found to make less excess mess.
Solid objects are constructed of atoms.
If you want to make a machine, you construct it out of interlocking parts like beams, plates, bolts, axles, gears, belts, and so on and so forth.
If you want to make an electronic circuit, you make it out of wires, transistors, diodes, resistors, etc. Even if it’s all on a chip there are still those separate patches.
The body of a plant or animal is constructed from cells, tissues, organs, etc.
Ecosystems are made from different plants and animals and works over long periods of time via cross-over, mutations, replication, and natural selection.
The universe is constructed from asteroids, moons, planets, suns, stars, black holes, interstellar clouds, galaxies, and so on and so forth.
The church appears to be constructed out of Christ, Mary, the saints, the angels, sinners like us, etc., with intercession being analogous to the interlocking moving articulated parts in articulated mechanisms like steam locomotive wheels with their coupling rods.
It appears that in God’s plan(s), He shows a great fondness for interlocking separate parts. Why? I don’t know, but He just does. Maybe in a parallel universe of the Tegmarkian sort, he does things in another way, but in this universe and with the heaven, hell, and purgatory we currently seem destined for, that’s how He does it.
You might as well be asking “Why love?” or “Why something rather than nothing?” Those subjects too have been discussed at length on this forum, with people all giving their various answers (and I have weighed in on some of them), but I think you’re basically just running into a wall here.
God likes interlocking parts and pieces, and that’s the way it is.