I m in Asia, we need the ability to validate 13 different exchange regulations and Java helps more than C++ as far as I can observe in team work, modularity, forcing some sort of okay common practice etc. The guys in the US have it easy with regard to logic so can throughput fast enough in Java to only switch fast clients to FPGA without the need for C++ in between.

The guys in London have nowhere near the volumes of APAC or the US. They can trade with excel if they want.

Might be, doesn't change the fact that plenty of business in finance have moved into GC based languages, reducing their use of C++ into niche use cases.

Just like using C or C++ hasn't taken away that some niche use cases still require coding in Assembly.

It isn't only Java, C#, F#, Haskell and OCaml are also tooling they reach for.