Maintenance is a promise.
A product's continuing promise needs resources, knowledge and limits. Quiet use does not make those obligations disappear.
A product can stop being interesting to its makers long before it stops being important to its customers. For the team, it may be a quiet item in the portfolio. For a customer, it may hold the records needed to finish this month's work. The absence of new features does not reduce that dependence. It may mean the product is doing its job.
The business still needs someone who can investigate an error, understand an old exception and explain what changed. That work arrives according to the customer's need, not the team's enthusiasm. It has to fit somewhere in the economics.
What the promise continues to cost
The promise needs a continuing definition. Which parts of the service must remain dependable? Who investigates a fault? What can a customer expect when something is no longer supported? A quiet product does not necessarily need constant new development, but its basic obligations still need people and resources.
Those resources can be funded in different ways. A business might deliberately subsidize a product while it learns or while it serves a wider purpose. The subsidy is still a choice with a cost. Naming its source and review point makes it possible to distinguish a supported commitment from work everyone assumes someone else will absorb.
Knowledge is part of that cost. Suppose the original builder can fix a problem quickly, but a colleague cannot tell where to begin. Hiring another person does not immediately remove the dependence. Someone has to make the reasoning understandable and someone else needs time to learn it. The business should judge that investment against the consequences of waiting for one unavailable person, rather than treating every product as needing the same level of cover.
A useful maintenance review starts with an ordinary failure in a product whose maker has moved on. Identify who could understand it, what information they would need and what work would have to pause so they could repair it. An unowned step is a gap in the plan. A promise to find time later leaves the gap intact.
When a commitment changes
The commitment may eventually need to shrink or end. Keeping a service available without adequate care is not automatically kinder to customers than closing it. Closure needs attention to the dependence the business created: notice, a clear account of what remains available and whatever usable records or alternatives it can responsibly provide.
The quiet years are part of what owning a product means to us. A service can become less interesting to its makers while remaining essential to someone else's month. That unevenness will not disappear with a better launch. It gives us a reason to think about the life we are prepared to support whenever we become interested in starting something new.