First, there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac. This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.
There are no known viruses, i.e. self propagating, for Macs. There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.
Anti Virus developers try to group all types as viruses into their ad campaigns of fear. They do a poor job of the detecting and isolating the adware and malware. Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.
There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is desshoigned solely to seek out adware and known malware and remove it. The free version is more than adequate for most users.
If you have a desktop Mac at home behind a good router you're well protected and don't need the FireVault turned on. However, if you have a laptop and are out and about a lot using public WiFi networks then definitely turn on the FireVault.
So follow the excellent advice you've already received here and uninstall those unnecessary apps.
