Speaking of which, why is there no central database of all articles with metadata? A "journal" would simple consist of the articles tagged by a particular set of people as peer reviewed.
That's almost what Google Scholar is. It captures nearly all journal articles (especially in English).
It depends on the country but an approximation for US biomedical research is https://pubmed.ncbi.nlm.nih.gov/
although that's only journal-published information.
PubMed covers stuff from other countries as well (as does European PubMed).
Oops. Yes. What I meant to say was that US granting agencies often require published results to be catalogued through PubMed. Not that PubMed only catalogues US-based research.