If you have one product (like startups) it is easy to port. You have, in relative terms, nearly unlimited budget and incentive to stay on the latest and greates

If you have one product (like startups) it is easy to port. You have, in relative terms, nearly unlimited budget and incentive to stay on the latest and greatest. If you work in a place where you develop many products for many clients, budgets are lower and you have much to maintain and develop. Porting is in my experience almost never done, because there is no business case to justify it.