Unfortunately the criticism from that link is absolutely correct.

Moreover, at that link it is shown only the ugly way in which RISC-V does multi-word addition.

Checking the standard arithmetic operations for overflow is much more horrible and inefficient than that, and checking for overflows must be done in any program that claims to follow safe practices.

Unlike in software, computing the carry and overflow flags in hardware is absolutely trivial and the extra gates needed for this add a cost that is below a rounding error in the total chip cost.

With Z80, it was much easier to compute arithmetic expressions than it is with RISC-V, especially when working with big numbers and especially when mandating correct computations, with no undetected errors.