Yes, most browsers have moved away from tracing JITs, but I think PyPy still uses it in addition to LuaJIT. The reason I brought it up was because tracing JITs, as far as I am aware, can give very good performance in the best case where your trace actually works (which is of course a bit of a dirty trick, but when you're up against C++ it's hard to play fair…)

Do you know why browsers moved away from tracing JIT?

Well, one reason is probably because they don’t perform well on programs that cannot trace well.