I’m not sure I’d say all the abstractions break down. If you and your team can agree on a subset of C++ features and patterns that work really well, you really can have some nice, clean code that yields both effective abstractions and good system-level results.

The problem with C++ is that it’s effectively a giant pile of tools, that keeps getting new tools dumped on the pile every few years —- some of which meant to “replace” older tools, yet rarely remove any tools (for fear of breaking backwards compatibility). So the pile keeps getting bigger and bigger, until it some day collapses under its own weight of complexity (maybe).

Skilled craftspeople can still use these tools to great effect, but there is at least an organizational overhead and danger from how cluttered and huge the set of tools is: every person or team may use a different subset of tools due to differing preference, not knowing about all the tools, not using some tools “properly”, using the “bad” tools, etc. etc.