The actual feasibility and reality of building them with today’s technology aside.
Would they work more efficiently than many our machines of today.
If you had a machine that was an extension of your body but was 100 of times stronger and durable.
Could swap out hand held tools and so on.
It wouldn’t work for moving raw material
Construction though you could build very quickly
Modern body armour will likely evolve into power armour if humans troops aren’t made redundant by drones.
Thinking as I’m watching Gundam on Netflix
The mech so out classes conventional weapons