This is a great question. I have worked in and studied civil society in more than 30 countries over 30+ years and what you find for the most part is that, depending on how you define NGOS (if you count religious organizations, political parties, and media organizations which ARE the most sustainable because they are part of the culture, have membership dues, and also sell services), most of the new NGOs are not sustainable because they are either foreign donor funded or become donor driven in their own countries and are dependent on funds of elites (which gets them more funds for a while but corrupts their impacts). In general, they don't have long-term strategies about anything, either for their impacts (which usually treat symptoms of problems in the form of charity and relief rather than addressing root causes) or funding. And there is a contradiction in that those that may be more sustainable are those that know how to advertise and pander but are, paradoxically, usually those that then have little real impact. You might find some of my NGO indicators of interest, on my ResearchGate site, such as:
“A Screening Indicator for Holding International Non-Governmental Organizations (INGOs) to Standards of Professionalism and Accountability,”
“A Poverty Reduction Accountability Indicator for NGOs and International Organizations,”
You might also want to look at what is happening now with the focus on businesses that are engaged in social change through 'green products', for example. Businesses are more likely to be sustainable and if they have social objectives they can try to compete against other businesses but they have to do it through competitive prices or they just sell to a very small segment of people who pay a premium for what they view as socially responsible.
Most of the international projects that I have seen that claim to develop "civil society" actually just want to copy an international model and buy influence so they rarely focus on the question you are raising. You might also like this piece:
يصعب كثيرا ضبط معنى المنظمات غير الحكومية وبالتالي دورها في التنمية وخاصة في مجالات حقوق الإنسان وحماية البيئة ومكافحة الفقر والاوبئة يخضع لمعادلات سياسية واقثصادية تؤثر في تدخلاتها ومدى ارتباطها باجندات اخرى داخلية وخارجية
Great question, which opens spaces for critical discussion and research in the third sector development. Usually, NGOs in the developing world follow the policies and procedures of their international donor agencies, such as INGOs or UN agencies. These include Procurement procedures, financial and organisational management procedures, Human Resources development and management policies, job descriptions for staff, complaint handling mechanisms, Do No Harm, HAP standards, Sphere standards (https://spherestandards.org/), and code of ethics and conducts, for instance.
Some donors ask the local NGOs to follow specific policies and procedures to access the funding sources, which depend on the donor agencies. Moreover, NGOs must be registered with respective government bodies, and their annual accounts must be audited. Furthermore, the projects require to be developed and implemented with stakeholder participation in most cases. Moreover, program cycle management procedures should be in place (planning, implementation, monitoring, evaluation and reporting).
There are several policies, procedures and standards relevant to specific intervention areas, such as working with women and children, war-affected and displaced people, indigenous people and vulnerable communities, emergency and disaster interventions, human rights violations and torture victims, migrants and asylum seekers, and even in environmental conservation or psychosocial and healthcare interventions. Further, I/NGOs follow the UN charter, policies, procedures and principles in development interventions, policy, advocacy and campaigns.
You can get a different perspective on development interventions through Give a Man a Fish by James Ferguson (https://www.dukeupress.edu/give-a-man-a-fish).
NGO's play a formidable role in the quest for good governance in developing countries. These organisations must build local capacities to enable the people to own the change process
. NGOs must be accountable, and transparent, build networks to create stronger communities and provide training to them on monitoring and evaluation so that communities can form educated opinions on how they are being governed.
True NGOs or civil society must practice what they preach to government by ensuring that stakeholders participate and follow the rule of law, in addition to going all the way to meeting the standards and principles of good governance. However, most NGOs do so to meet donors and government requirements.