As a dev turned entrepreneur one thing I will do when selling projects is talk to clients about software as a depreciating asset. While there are some limitations to the comparison this framing makes sense to business people in general, especially well with finance or operations departments, and can work with internal stakeholders too.
The sources of the depreciation are tech debt and general turnover/churn in the method and process within an industry/vertical (like if you built a web app in 2002 based on ASP.NET, it's pretty tough for that to be a lively project today).
We know there are systems out there that have been running well and doing their job for 30 years, and there are systems that need to be replaced/rewritten from scratch every couple of years. Which one do you want to buy/fund/budget for?
If the customer or stakeholder only cares about a two year horizon you approach the project one way. If they say they want this thing to be firing on all cylinders 10 years from now then we approach it and price or budget for it differently. When you talk like this it doesn't sound too weird to introduce the idea that we should do an annual tune-up to a system that they don't want to have to replace until 2035. The tune-up is how you get 15 years of life out of your intellectual property instead of 10, this is how you sell time to pay down tech debt. The eventual rebuild is also part of the discussion (not if it will happen, because it will. But when it will happen is something we can influence, so the framing can be, would you rather do an expensive rebuild every 10 years, or do it in 15-20 because you paid for a regular maintenance along the way?).
Boom now in their head this software you're writing is like a car. Everyone understands cars. A car has a lifespan. If you didn't go to the mechanic and do your annual scheduled maintenance and the car breaks down, that's what you get for being cheap. Like I said big ops and finance departments actually really like the idea of a tuneup that prevents the car from breaking down. They're used to thinking about that with lots of physical assets anyway. A marketing department at a startup maybe not so much but their time horizon is usually short anyway.