High-yield shares are a popular investment strategy, offering passive income through dividends. However, they come with risks, as dividends are not guaranteed and high yields can sometimes indicate doubts about sustainability. The FTSE 100, comprising the nation's largest listed companies, is no exception. While it boasts large, well-known firms like Shell and Vodafone, these giants are not immune to dividend cuts, as evidenced by their past actions. Despite this, the FTSE 100 still pays out substantial dividends, with over £1 billion per week in the first quarter of 2026. Among the highest-yielding shares are Legal & General (8.6%), Standard Life (7.3%), Land Securities (6.9%), M&G (6.8%), and Barratt Redrow (6.7%). These shares offer more than double the yield of the FTSE 100, which currently yields 3.1%. However, the sustainability of these dividends is a concern. Barratt Redrow has already cut its dividend this year, and the housing market's weakening demand could lead to further cuts. Standard Life, with its mortgage book and potential property market decline, faces similar risks. Despite these challenges, Standard Life's strengths, including its large customer base and established brands, make it an attractive investment. Its focus on the retirement-focussed financial services space, a resilient and large market, further enhances its appeal. The company's goal of raising the dividend per share each year and its strong financial markets expertise make it a potential long-term dividend raiser. In conclusion, while high-yield shares offer attractive income, investors must carefully consider the risks and potential challenges. Standard Life, with its strong fundamentals and focus on a resilient market, is a share worth considering for those seeking passive income.