Software Growth Period

https://gyazo.com/4220768990aa56b7302f7f813cb68e62

In humans, size increases during growth and does not change much thereafter

After the growth spurt, work hard to control your physical condition and size to live a long, healthy life, not to get bigger.

Isn't there a similar growth period in software?

Shouldn't a program that has passed its growth phase be refactored or its functionality gradually ported to a new system to maintain a "functional and flexible body" and live longer, rather than "fattening up" the code by adding new features?

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