Practical consequences of $Parity \notin AC^0$ Background
Circuit complexity $AC^0$ is defined as the set of circuit families (i.e. sequences of circuits, one for each input size) of bounded depth and polynomial size built using unbounded fan-in AND, OR, and NOT.
The parity function $\oplus$ with $n$-bit input is equal to the XOR of the bits in the input.
One of the first circuit lowerbound proven in circuit complexity is the following:

[FSS81], [Ajt83]: $\oplus \notin AC^0$.


Questions:
Let $EC^0$ be the class of functions that can be computed using electronic circuits of bounded depth and polynomial size using electronic parts like transistors. (I made up the name $EC^0$, let me know if you know a better name for this).


Can we compute $\oplus$ in practice using $EC^0$ circuits?

What about unbounded fan-in AND/OR? Can we compute them in $EC^0$?

Does $\oplus \notin AC^0$ have any practical consequences? Is $AC^0$ important in practice?

Why is $\oplus \notin AC^0$ important for (theoretical) computer scientists?




Note:
This post contains interesting questions but OP seems to refuse to make the post more readable and fix the misconception in it for some reason, so I am reposting questions from it. (It would be easier to edit the original post but currently there isn't an agreement if it is OK to heavily edit another user's post.)
Related:

Parity and $AC^0$

Why is parity not in $AC^0$ important? (Computational Complexity Blog)
I am not an electrical engineer, but search for online patents regarding switching circuits for parity gates, and all proposals (I found patents only until the end of the 1970s) discuss the size-versus-depth problem. All three patents I have looked at propose solutions of logarithmic depth, based on fanin-2 gates. So the answer to your first question is possibly "no".

J.J. Moyer: Parity Check Switching Circuit, United States Patent US3011073, 1961

A.F. Bulver et al.: NAND Gate realization of the n-input parity function, United States Patent US3718904, 1973

P.J. Baun, Jr.: Parity Circuits, United States Patent US4251884, 1981