"Infinite regress of causes and effects can't be real/ is illogical/impossible".
Why assume it is impossible. (Reality doesn't have to appeal to our common sense)
Why assume we understand what it actually IS as finite creatures.
Why assume that it is the only alternative to "uncaused cause"? Maybe there are million other alternatives we can't ...
An infinite regress is evidence that our thinking is incorrect. Such contradictions do not arise when our thinking is correct. They are found all over the metaphysics of our universities. They are not found at all in the philosophy of the Upanishads, which endorses a neutral global theory.
Why this is not regarded as a vitally important issue I have no ...
Okay, perhaps that was a bit pithy. There are indeed people who make these assumptions, and one can talk to their rationales if one pleases. There's a lot of people out there with a lot of opinions about what is going on. However, one can talk about the whole of philosophy, considering people who deviate from the "norm."