Your reference here is a 33 year old paper whose quoted observations and theoretical claims are totally out of date. The measured light element abundances are now consistent (and have been for decades).

The black body distribution of the CMB is the (confirmed, of course) prediction of the Big Bang. The structure, age, etc. all depend on the cosmological model, and the claims that no such model can explain observations is ridiculous, given the counterexample of the \Lambda CDM model, the cornerstone of the field for decades now, that explains them all.

It's almost impressive how obstinately you've convinced yourself of something so blatantly wrong and out of date, using only a reference predating the entire modern era of cosmology that you even admitted to not having read "for a while." A far, far cry from engaging seriously in a topic.

Like with the frontier LLMs, seeing commentary on this site on topics that I'm an expert in makes me seriously doubt whether I should lend any credence at all to what's said about those that I'm not.