Microkernels have always been slower than monolithic kernels, never faster.
There is zero chance that Zircon will be faster than Linux.
The classic example is Mach from CMU:
"When Mach was first being seriously used in the 2.x versions, performance was slower than traditional monolithic operating systems, perhaps as much as 25%... When Mach 3 attempted to move most of the operating system into user-space, the overhead became higher still: benchmarks between Mach and Ultrix on a MIPS R3000 showed a performance hit as great as 67% on some workloads."
There is zero chance that Zircon will be faster than Linux.
The classic example is Mach from CMU:
"When Mach was first being seriously used in the 2.x versions, performance was slower than traditional monolithic operating systems, perhaps as much as 25%... When Mach 3 attempted to move most of the operating system into user-space, the overhead became higher still: benchmarks between Mach and Ultrix on a MIPS R3000 showed a performance hit as great as 67% on some workloads."
https://en.m.wikipedia.org/wiki/Mach_(kernel)