"Asking the real questions here: is Adobe Flash Player Safe? I would wager to say “no”; there have been far too many malicious attacks using Adobe’s Shockwave Flash for deployment and dissemination of malware.
Regarded mostly as a vulnerability rather than a practical software development, Adobe announced in early July 2017 that it will discontinue support for Flash Player by the end of 2020."
https://heimdalsecurity.com/blog/is-adobe-flash-player-safe/
". The only issue was that Flash has some major security issues that are incredibly easy to take advantage of, and as time went on, Flash became notoriously known as the entry point for many a security breach. Annoying ads, backdoor malware installation, and data collection have found their ways onto many a PC thanks to the holes in Flash’s security."
https://lifehacker.com/you-really-shouldnt-be-running-adobe-flash-player-anymo-1829721122
This is why so many browsers automatically disabled it and you had to give it permission to run. Uninstall it from all your browsers