So a recent paper argues:
After nearly 13.8 billion years of nonstop expansion, the universe could soon grind to a standstill, then slowly start to contract, new research published in the journal Proceedings of the National Academy of Sciences suggests.
In the new paper, three scientists attempt to model the nature of dark energy — a mysterious force that seems to be causing the universe to expand ever faster — based on past observations of cosmic expansion. In the team’s model, dark energy is not a constant force of nature, but an entity called quintessence, which can decay over time.
Brandon Specktor, “The universe could stop expanding ‘remarkably soon’, study suggests” at LiveScience (May 2, 2022)
What would a contracting universe change?
The paper is open access.