I think it is more accurate to say no one agrees on how to understand it rather than no one understands it. Clearly people understand it or else they couldn’t use it to make new inventions and discoveries. It’s just that math doesn’t inherently give you an ontology. That requires you to apply a level of philosophical interpretation to the math, and quantum mechanics is very underdetermined when it comes to the ontology. 10 different physicists who are all experts at the math can look at the same equations and interpret the ontology differently. But I wouldn’t say they don’t “understand” it because their viewpoints can all be logically consistent.
I think it is more accurate to say no one agrees on how to understand it rather than no one understands it. Clearly people understand it or else they couldn’t use it to make new inventions and discoveries. It’s just that math doesn’t inherently give you an ontology. That requires you to apply a level of philosophical interpretation to the math, and quantum mechanics is very underdetermined when it comes to the ontology. 10 different physicists who are all experts at the math can look at the same equations and interpret the ontology differently. But I wouldn’t say they don’t “understand” it because their viewpoints can all be logically consistent.