Our original matrix_fib used Python's arbitrary-size integers, which are slower than gmpy2 by a lot. To compare Binet's formula and matrix exponentiation on an even footing, we should convert the latter to use the faster GMP version, the same library that gmpy2 uses.

Now let's see what happens when we compare them!

Code
Output
81104 81104

Our original matrix_fib used Python's arbitrary-size integers, which are slower than gmpy2 by a lot. To compare Binet's formula and matrix exponentiation on an even footing, we should convert the latter to use the faster GMP version, the same library that gmpy2 uses.

Now let's see what happens when we compare them!

Code
Output
81104 81104