1. You can’t avoid some hand digging even with tools.
2. Price equipment rentals into the bid. Big companies have big overhead and often even if they OWN the equipment they charge for it. I’ve seen charges per labor hour and by craft/title (field electrician, foreman), plus pickup trucks, welders, man lifts, you name it. Plus those big companies may own equipment but it still needs service and they can’t ever own enough so they rent too. And they have the accounting departments, storage and maintenance on that equipment, buildings, HR departments, and owners yachts to pay for. So they honestly can’t compete with small companies and go after huge jobs where they can spread out the overhead and still make money. Don’t be afraid to include equipment charges too. If someone balks, roll up the costs. So if you have a detailed bid with say $10k materials, $6k labor, and $1k equipment just change it to $17k or $10k materials and $7k labor. Does it matter that not all the labor is in that number? No.
3. The companies that own cranes, etc., are mechanical or rigging companies. Look at any mechanical crew and what do you see? Trucks and trailers everywhere, and tons of people. Mechanical jobs are typically 90% labor. They are spreading all their overhead over the mechanical crews, and mechanics, bricklayers, concrete laborers, etc., are cheaper than millwrights and electricians. In a typical say new chemical plant project with a million dollar budget the electrical might be say $100k. That’s a pretty typical number. Masonry might be say $100k. So the focus is on the $800k mechanical cost. The problem for you is the big contractor can cut the electrical bud by say $50k and just make it up on a $800k job some place else so they can outbid you every time on big jobs just to get the entire $1 MM job. But they won’t touch a $25k electrical only job which is fine for someone starting out.