There is more focus of late on theories of "emergent gravity", i.e., that gravity is not a fundamental force. The most interesting one to me is so-called "entropic gravity", which also resolves the issues plaguing the theory of dark matter and gives credence to MOND. Such theories have been long derided by old-school physicists raised in the golden era of quantum mechanics (and their acolytes), but have surprisingly powerful explanatory power that other theories cannot achieve without tacking on seemingly arbitrary or else otherwise unmotivated factors. Dark matter especially has always been suspect to me, since even after all this time, it is defined as little more than "the gap between our models and observations" with no strong underpinnings that would explain its existence in satisfying ways.
I am not affiliated with this blog in any way but find the arguments compelling: https://tritonstation.com/
I am not affiliated with this blog in any way but find the arguments compelling: https://tritonstation.com/
Here's an interview with a researcher who is also trying to move beyond quantum formalisms for spacetime vis a vis gravity: https://www.quantamagazine.org/the-physicist-who-bets-that-g...