The tired light theory is an alternative explanation to the red shift of distant light that says it’s not because distant objects are all moving away from us but instead that the light somehow loses energy as it travels, which lowers its frequency.
There was another alternate theory that suggested everything was shrinking instead of the universe expanding (thus wavelengths seem longer by the time they get to us).
Personally, I’m more “open to the idea” than “sold” for the idea of the universe’s accelerated expansion. I like theories that eliminate the need for dark matter or energy, especially given that the current ones requiring them assume that they make up 95% of everything. It just seems more likely that we don’t understand things as well as we do than to assume we’re right about everything we think but just need to add 19 times what’s already here to balance it all out.