"There is still a long way to go" means that there are still many opportunities in the future. This idiom is usually used to encourage people not to be too anxious or uneasy, but to remain calm and patient.
The original intention of "a long stream of water" is to let the water flow slowly, which is a metaphor for saving property, calculating carefully and making long-term plans. This idiom emphasizes the planned and controlled use of property in daily life, avoiding waste, being patient and calm, and not rushing for success.
Therefore, we can use the phrase "there is still a long way to go" to encourage people not to rush for success, to act patiently and plan, and there will be many opportunities and time to achieve their goals in the future.