That makes sense, because it has the potential of increasing the space requirements exponentially, thus making upgrades inconvenient or even impossible.
Personally, I take a system image before every feature upgrade, and would recommend everybody else to do so as well.
While this may be enough in general, it’s really a good idea to have the system take regular backups for data that is even remotely inconvenient to replace; these days, with cheap mass storage and reasonably quick transfers, there is really no good reason not to do so.
Windows 10 offer integrated backup options, and there are solid third-party alternatives available for free, too.
