That's really strange that that was what you've read because log cultivation is actually the norm for most mushroom farming operations. You do get the most bang for your buck using logs because they are very nutrient dense compared to straw or some other substrate that you might use in a growbag. If you have land with a good supply of timber, it's even better since you don't have to pay for wood. on the other hand, you usually have to wait a year or two before they'll fruit, depending on which species you're growing (and not all species are suitable for log culture), but they should also fruit for a good 4-6 years once they do start from what I've heard.
Mushrooms really aren't too hard though, to be honest and log culture isn't the only good way to grow them. You can get all high tech and isolate strains using agar which is fun but not really necessary unless you're going for very specific traits. You can just as easily pour a spore slurry of oysters or king stropharia over some wood chips and keep them moist and you'll probably get nice sized flushes. If you have chickens or goats or some other type of animal, you can plant stropharia near where they are kept and they will clean up a lot of the bacteria that is in the animal feces and you'll also get mushrooms out of it. Basically you can inoculate any wooded/mulched path in your garden with some type of mushroom or another, and as long as it's kept moist and shaded there's a good chance you'll get mushrooms. They're seriously underutilized in permaculture, honestly. They're easy, fast, fun, they are great remediators, many form beneficial associations with plants (elm oysters do well in gardens, especially with brassicas), and they're really good to eat.