Expansion of the universe is misunderstood by scientists. Everything redshifts. Everything can react. Particle volume varies. Nature shapeshifts the Noether cores in spacetime aether particles, photons, and neutrinos all depending on velocity and the local potential aura. Photons pass by aether particles that are expanding in place.
Reactions shed energy by repurposing tiny Fermi-Dirac aether particles and spinning them up as photons with Bose-Einstein flatness or neutrinos with not enough energy to become photons, so their apparent energy oscillates.
The point is that there are a lot of processes going on simultaneously that are changing the size of Noether core particles dynamically. At large scales the net sum of these processes is a steady state universe where things swirl around to some degree, but there is no outward expansion as a whole.
Note that these shapeshifting processes, particularly the ones for the life cycles of the photon and the spacetime, implement Einstein’s geometry at scale. In other words, most of spacetime by volume is dominated by very small low apparent energy Noether cores. This is doubly true since all matter is formed upon Noether cores.