Pegasus

Pegasus is real, yes. Pegasus can be used to exploit and exfiltrate pretty much anything of interest to the user. Sometimes with user interaction, sometimes with no user interaction. There have been Pegasus-related patches going back several years, too.

The answer to the question “should I install a security update?” is approximately always “yes”.

Yes it's safe to install 14.8.

Pegasus is not Spyware itself, it allows spyware to be installed. However, the chance of you ever getting attacked are pretty much zero.