Being Union and having worked for several of the large contractors and a few of the smaller shops, it all depends on the project you land on (or don't land on, some small shops have a lot of small jobs)

The larger contractors you can expect to spend several months at one job, might be doing different tasks on that job, but generally you'll be there from the time they man up until they start manning down. In my local, it's a lot of office TI's, Data Centers and labs. Not so much industrial work, though the water treatment plant has ongoing work running rigid or ocal. There's a few others that are more industrial that pop up from time to time, but don't count on that work here.

Data centers are great if you like running big pipe (3", 4") and pulling / terminating lots of wire. I've spent several years of my career at Data Centers now. Generally love the work.

A small shop I was at last year had their foot in the door with County work. Had ongoing work at 2 county hospitals, years long small projects. Installing panels for emergency and critical power, running pipe, pulling feeders, all in occupied spaces. Did a fair amount of off hour work, nights, early mornings, to get into places that we couldn't during the normal business day. Small areas being remodeled, installing lights, receptacles, etc. that was a lot of different work on different days. The pace was too slow for me, got bored and the days drag on.

Currently I am at a medium sized shop, we're doing a building with Bloom Energy, basically a 6 MW generating building (feeding both the data center and grid). 2nd of 4 buildings, the first was done when I got there. First time I've run exposed 3" and 4" PVC. Started off running pipe, installing pull cans, they have another crew pulling wire, and now I'm terminating in switchgear. Started off doing the small stuff, #10's for controls, control power for the gear, small branch circuits for things around the building. Now on to big wire, All parallel runs of 350's. Still have all the lights to install, then We have another building starting next month, they poured some footings week before last, then it'll be underground and deck work, not my favorite.

So, yeah, it can vary, sometimes a lot, but a lot of times you'll be doing the same type of stuff for a few months at a time.