This has nothing to do with software-center itself. The only way you are going to make this better is to get the upstreams to do the requisite packaging work and make the packages available as updates through software-center by publishing them via the web site for managing one's applications published to Ubuntu. It is "easier" to upgrade individual applications on those proprietary OSes, because the developers are taking the time to publish those packages through the Apple store, or Google Play, or similar means.
The developers who put together the Ubuntu release every 6 months understand the frustrations with this, but bug reports are not a channel for dumping complaints. If there are specific applications that fall into this category of not being up to date enough on the version of Ubuntu you are using, as shipped in that version of Ubuntu, then you should ask the developers of those applications to help by doing the packaging work to get the app published through the Software Center; in the same way that they are doing that work to publish their apps in the Apple store.