Also because many devs do not understand multiple execution layers. From react devs who never heard of javascript native loops to Spring devs who have no idea h

Also because many devs do not understand multiple execution layers. From react devs who never heard of javascript native loops to Spring devs who have no idea how sql looks to c devs who have never used a memory heap tool to node devs who never seen io performance impact to ..... You need an all seeing eye to make things performant. Those are scarse. Probably one in the 20 devs max.