do we need a dedicated firewall device for a company?

i am a mikrotik user, so i was going to check my friend's church network because they have an internet problem, they are using SonicWall as firewall, never touched this system really, so my question is, do we really need a dedicated firewall device or system, can't we just use mikrotik firewall for the job? what is the pros and cons if im just using mikrotik firewall or using dedicated firewall device, THANK YOU