Google is not a good example to look at if you are thinking about enterprise software as these need to be supported long term and Google is not very good at that. They have a history of making breaking changes and discontinuing products.
Microsoft is a much better example for business software as they are (were?) paranoid about backward compatibility.
You're confusing software engineering with corporate product support. You can have top-notch ongoing lifetimes for trash products. See for example SAP or anything Oracle.
Product support is an integral part of enterprise software engineering.
Product management does not know what adding a new feature or deprecating an old feature means. It is the responsibility of engineering to provide the dependency matrix.
For example, engineering usually tells product, if you change feature A, then it will also affect feature B, C and Z. Otherwise you may end up with contract breaches and SLA violations.
Product lifetime and providing incremental features is a big reason why SAP and Oracle have been successful in the enterprise space and people still pay a lot of money to buy them.
Microsoft is a much better example for business software as they are (were?) paranoid about backward compatibility.