Linux has a more efficient filing system than windows and tries to store blocks of data on the same place on the hard drive/ssd when possible so there is much less fragmenting. Yes, some fragmenting will occur but it generally is something most users need never worry about. In some cases writing/deleting very large files(i.e. full hd movies etc.) could possibly cause a need for defragmenting to keep the distro running efficiently. https://www.techwalla.com/articles/how-to-defrag-in-linux
It is possible for viruses to be developed for Linux, and in fact a very miniscule number do exist, however they are so rare that Linux users really should not be concerned about them as long as they stick to the official repositories of their distro, install regular security updates, and download/install 3rd party software with great care and discretion. After all, it is possible to have a plane crash into your home, but such an event is so rare that I don't spend any time worrying about it. Linux is generally immune to the vast number of Windows viruses although such viruses can be transmitted to Windows machines - in Linux they are just a useless piece of code.
I just used Libre Office as an example - there are other alternatives such as Only Office that is closer in function to Microsoft Office and in fact some people like better than Libre Office. https://www.onlyoffice.com/
I think that if people are having problems/complaints about using Windows, they should definitely give Linux a try. With the hundreds of distros available there is a very good chance that they will find something that suits them well. However, someone trying Linux should have at least a minimal level of technical competence and be willing to take the time to learn new things.