> I think that this is largely a sign of various small inefficiencies and design decisions adding up in any piece of code - and the larger the codebase, the more of these there will be, which is why for non-trivial programs C++ can actually be slower than Java. Not because the ideal C++ code is slower than the ideal Java code (with realistic runtimes), but rather because in practice you'll never get to this ideal code.

but this isn't what we observe in practice: all the C++ apps I know and use regularly consistently work better than their Java equivalents AND perform faster. Jetbrains IDEs are unuseable for me coming from Qt Creator and I don't understand how anyone can stay sane with them - and I try CLion pretty much every year since it's been announced.

Besides, what matters to compare language is not how the ideal, infinitely optimized app looks like, but how the average one does. And, to me, the average Java app is unambiguously terrible when compared to the average C++ one.