Hybrid bonds are instruments that help optimize capital structure but come with higher cost of capital and complexity; ENGIE in 2022 shows substantial long-term borrowings and current liabilities, with a mix of debt and equity. Notable items: long-term borrowings around 28.083b EUR (2023: 28.083b; 2022: 30.458b), noncurrent derivatives and other liabilities, and significant equity components including deeply subordinated perpetual notes (3.393b in 2023; 3.767b in 2022), which are effectively hybrid equity-like instruments. The presence of deeply subordinated perpetual notes already indicates reliance on non-traditional hybrid instruments. However, profit/loss from continuing operations is negative in 2022, and net financial income loss is large negative, while cash flows from operations are robust but financing activities show sizable borrowings and repayments.

Given the mix, ENGIE appears to use hybrids to supplement capital but not dominate; there are existing perpetual notes and other equity-like components, but debt and financing activities dominate, with typical corporate debt structure. Therefore, a moderate use of hybrids is likely appropriate to balance flexibility and cost, not full reliance. I would rate at 50% of capital structure reliance on hybrid bonds.

Final answer: <answer>50%</answer>