When I was a young boy back in late 70's, early 80's, I had a great lawn/landscaping business where I had 30+ lawns to cut every week. It was between ages of 13-18, all through local newspaper ads word of mouth and those grocery store bulletin boards with your ad and cut out phone # tags. I did everything, cut grass, did flower beds, weeding gardens, storm windows, eave troughs, leaf raking, snow blowing, house siding washing...the whole package.
First year borrowed my dad's AMF lawn tractor and push mower, 2nd year bought my own tractor, mower, weed eater and 4-wheel wagon to carry it all. By the end, I had enough cash saved up to pay for my first 3 years of university including apartment and food, books, beer, so you can imagine how much I made. It was awesome. I ended up with a big bank account, a great work ethic and responsibility, as no one needed to tell me to get my lawns done after school. Had my wagon rigged up with rear lights to safely get home in dark in the fall when days were short, many times with a wagon load of leaves or clippings to our own compost pile at home.
I think if a person is smart and doesn't overextend themselves with fancy equipment/truck, there is money to be made. Lots of money. And it is cash-ola! And if you can do all the jobs, gardening, eaves, snow blowing...there are a lot of older people needing that work done by a reliable trustworthy person.