[cjfd]

Well, pipes are very nice and useful for small processing tasks. "I want to know how often the word 'Parameter' occurs in the source files inside this repository." That is great! pipes are your friend. They are the fastest way known to mankind to solve this problem. But they are also fragile. You may not have thought about the fact that the word NoParameter also occurs in the code base and you did not want to count that. Now, when writing something big and complicated pipes simply cannot keep up. Nobody wants a browser that is actually 100 small executables that communicate over pipes. It will be horrible. The IPC mechanism that you are looking for and that can actually handle what is needed for a browser is called 'function call' and it was already quite popular when C was introduced....

The interaction mechanisms between services, e.g. REST calls, is somewhere in between pipes and function calls. They are a bit more reliable than pipes and less reliable than function calls. They can be used for more complicated task than what pipes are used for but should not be used for task that are so complicated that they need function calls.