Depends on where you live. Texas is a right to work state, so they don’t have to fire you for cause. Additionally, a lot of places have a line item in your job description called “Other duties as assigned”.
When I worked as a sysadmin for small companies about 12-13 years ago, those duties included climbing in the ceiling running drops from a secured server room to a colo, setting up cabs in both spaces, building desks/cubicles, wiring cameras for the security system, and some other tasks that larger companies generally hire a contractor to do.
That was in addition to configuring switches, setting up jboss servers, acting as a DBA, and other sysadmin duties.
That being said, I did think of another Pro. At larger companies, you tend to have dedicated DBAs, Network Engineers, Data Center Techs, etc. At a smaller company that’s ALLLLLL you. So you get a lot of crossover training. When I started as just a front line ticket maker, I knew how to program in action script (flash games), and that was it. I got promoted to a DC tech, and eventually became a sysadmin for a hosting company. Then moved to a smaller SaaS company where I learned AD, Email, Phone Systems, PHP, Perl, how to write SQL, how to do RFPs and a whole host of other things.
I went in only knowing how to setup ghost, ios (cisco) and kicking/racking servers. Left with a lot of skills that helped me elsewhere.