Projects, are to many people, the place development is done and where all focus should be put. With this approach the maintenenance activities are forgotten and/or reduced into something that is only a cost. This is a real problem and the root to many evils in organisations today. The reason is that by its very definition a project has a start, a pre-planned life and a closure/death. In fact this approach very often hampers the possibility to financially motivate efforts in automation, retrospect, reuse and continously improve processes between projects.
A product can be created, continously changed and ultimately phased out based on what value it brings to the company. The lifespan is much longer than a project, naturally so because a project is a major change in a products lifecycle, but only that. Which means that automation, retrospects and reusability makes more sense in a financial perspective. Continously improved processes are also much more relevant because they are not only paper tigers but a very tangible assets supporting change and live outside the any project. Examples of product oriented assets are automated regression test suits, environment provisioning and known risks with mitigations. Since these live outside the project they can and should be reused and actually gives the company tools to govern the project improving the delivery of any project.
Another benefit is that since a product needs to motivate its existance in added value, any changes made to the product should be possible to quantify in added business value.
Agile practices are focused on maintaing a product in evolutionary steps, iterations, based on a known baseline i.e. assets in a deployment pipeline. This means that maintenance is elevated into the new normal where you engage in smaller or bigger changes that can be done in the form of projects, or not. In essence Agile development practices are really an advanced form of maintenance work and projects specific changes where you actually can specify in some detail the outcome.
From a funding perspective looking at Agile as an advanced maintenence activity makes more sense since you have similarities like not knowing the actual outcome, having a line organisation over time supporting and maintaining all forms of assets and experiences.
There are certainly situations where Agile engagements are best suited and also situations where traditional projects are best suited. In any case, development can be benefitted by the guardrailes created with a product perspective on the lifecycle.