That's why you need the appendices, so that you can check the details behind what is in the paper.

Journals have word limits, due to the restrictions of print, and because a 200 page paper is too much for most readers. But some of them will need some or all of those 200 pages (which is usually a shed load of tables and figures, not much text apart from protocols etc).

The quality of the research, and the way it was written up, cannot be assessed by those readers unless all the information is published. And the research cannot be implemented in practice unless it is described in full. There are thousands of papers out there that test a new treatment but don't give enough detail about the treatment for anyone else to deliver it. Or develop a new measurement scale but don't publish the scale. Or use a psychometric instrument but don't publish the instrument. This research is largely useless (especially if the details were never archived properly and there's no one still about who knows how to fill the gaps).

We don't (or should not) publish papers for CV points. We publish them so that other researchers know what research has been done and how to build on it. These days we don't just publish all the summary tables and all the analyses, we ideally make the data available too. Not because we expect every reader to want to reanalyse it but because we know some of them will need to.