I have been using Ubuntu for a while. If you're using your OS as your desktop environment, it's all about the installed software. But so far I have not always been able to find an easy and safe way to install new software on Ubuntu, and now I am considering Fedora as an alternative.
The easiest and safest way to install some software is to use the standard repositories that are installed with the OS and are considered a trusted source of software packages. During installation from this repository, software authentication and integrity is performed automatically on Ubuntu and Fedora. The advantage of Fedora is that the standard repositories have newer packages and are updated more frequently.
The second option is to install software packages from third-party repositories. The problem here is that you have to trust this repository, and if you want to double-check a software package before installing it, for example with virus total, it's difficult. In this case, Ubuntu and Fedora are identical.
A third possibility, and many programs are distributed this way, is to download an installation package. You must trust the source. But if it is a deb package for Ubuntu, the signature can only be provided as a separate file, and this is not always the case. And rpm for Fedora always contains signatures, the authenticity and integrity of which is checked automatically.
There is definitely a way to build software packages from source, but it can be tricky and is the same for Ubuntu and Fedora.
Correct me if I'm wrong in my consideration.