Well, I’ve been an industrial maintenance technician for close to 20 years now, and I’ve attended several vocational and technical schools, so perhaps you’ll want to read the following.
There’s a good reason why people say jack of all trades, master of none, because this is almost always true. Let’s look at the electrical field itself, it branches out on so many levels that even electrical engineers usually will specialize in a certain area. This is also why many ‘handymen’ usually make good carpenters and laborers, but lousy electricians, though they tend to push their luck by attempting to do the latter anyways. I’ve lost count of how many times I had to fix a handyman’s electrical work though they generally did a good job with other tasks.
There’s also the plumbing trade, which can vary as well on so many levels, to consider here too. Hydronic systems can be very complicated, even for a seasoned plumbing contractor, on the industrial/commercial level. There are complicated hydraulic and pneumatical systems too. Don’t even get me started with PLC, PC programming, CNC parameters, robotics, various electronic systems, etc.
As you can clearly see it’s almost certain that, at least on the industrial maintenance level, that it’s nearly impossible to even come close to mastering all trades/fields. I’ve worked with guys who had more and less education than myself, and I’ve never seen a tech be proficient enough to be an expert in several trades, though some like to think they are. Maybe it’s possible to master most construction trades, especially on a residential/small commercial level, but not on an industrial maintenance level.
Many companies today are creating positions with various titles, such as electromechanical technician, maintenance technician, tech (either I, II or III), etc. This is because they want people who know the basics of most trades, and some of those guys may be expected to be proficient enough to be on a journeyman level on at least one trade. Basically they’re paying you less to do more work, acquire more responsibilities, and to work with less manpower helping you. I’ve been trying to get out myself of this circle myself now, and I’ve started working on the side for now.
You can try building and apartment maintenance, or electromechanical maintenance if you want a taste of learning various trades. Look at your local vocational or technical schools, for many schools such as these offer those courses.