To determine the extent to which ENGIE's capital structure should rely on hybrid bonds, we analyze the provided financial data and market context:

1.  **Capital Structure Analysis**: ENGIE's total equity as of 2023-01-01 is 39,285,000,000 EUR, with "Deeply Subordinated Perpetual Notes" (a common form of hybrid capital) amounting to 3,393,000,000 EUR. This represents approximately 8.6% of total equity.
2.  **Financial Performance**: The company faced significant volatility in 2022. While "Revenue" grew from 57.87 billion EUR to 93.87 billion EUR, "Profit Loss" dropped sharply from 3.76 billion EUR to 390 million EUR. "Profit Loss from Continuing Operations" swung from a profit of 3.68 billion EUR to a loss of 1.79 billion EUR.
3.  **Interest and Finance Costs**: "Finance Costs" rose from 2.06 billion EUR in 2021 to 3.70 billion EUR in 2022. The "Net Financial Income Loss" increased from -1.35 billion EUR to -3.00 billion EUR, indicating increased pressure from debt servicing.
4.  **Market Environment**: The Swap Curves (5Y, 7Y, 10Y) show a dramatic increase in interest rates from 2021 to 2022 (e.g., 10Y Swap average rose from 0.053% to 1.927%). Higher interest rates make traditional debt more expensive and riskier, increasing the attractiveness of hybrid bonds, which provide equity-like features (e.g., non-mandatory coupon payments, perpetual nature) to support credit ratings without diluting shareholders.
5.  **Recommendation**: Given the high cost of debt, the sharp decline in profitability, and the need to preserve cash while maintaining a stable credit profile, a conservative but meaningful utilization of hybrid instruments is prudent. Moving from the current ~8.6% towards a 25% target represents a balanced approach that leverages hybrid capital to optimize the cost of capital and maintain financial flexibility in a high-rate environment, without over-leveraging the structure with high-cost hybrid coupons.

<answer>25%</answer>