I've got a mostly desk/office job but I'm often on the shop floor. Since coming back from furlough it's been all hands on deck. I've been working on the shop floor with the directors too at times. It's about fewer people doing the same amount of work as before but occasionally that doesn't work so wen get stuck in. It's been more and more lately. As a result what you called functional fitness has started to kick in. TBH it's partly learning how to lift the heavy or irregular stuff? Bending over, dragging, pushing, etc. Don't tell HSE but at times it's simply easier to lift the heavy stuff on your own than finding someone free to help you. I've lifted 38kg+ of large and difficult to grip objects and lift it over a metre high, even once onto my shoulder. You can feel your strength improving but at least part is technique in lifting such things.
However despite that physical work leisure activity doesn't become easier. I'm no better at walking up a steep hill because of functional exercise through work. Wrong kind of training I guess.
What I need is CV exercise, core exercises and strengthening major muscle groups for general health and for outdoor activities we do. It is why I like good rowers and this versaclimber because they provide excellent CV training but also a degree of physical strength training with it. You're using major muscle groups, which raises your heart rate, but you're moving in a way that also uses secondary muscle groups that work with the main group. It's similar to functional training because that uses other muscles that work in a stabilizing way with the main muscles being exercised.
It's why resistance pulley type of weights machines are a bit flawed because they focus too much on a small muscle group. Whereas lunges with weights provide a dynamic strength training that works your core muscles with your leg and arm muscles because they stabilise you giving you balance. Or that was kind of what the trainer told me years ago when she got me onto my last reprogram before I left the gym. I didn't give up because it was so much harder but because I decided not to waste my money on membership as in used it less and less.