I can understand why some people prefer to experience Europe (or any other destination) on guided tours rather than on their own. Tours are easy. They're non-threatening. And they can be realatively inexpensive. But they're just never as rewarding as independent travel.
Another point is that many, if not most, tour directors lead their sheep to shops and restaurants from which they derive a percentage of the "take." These are seldom "bargains," and they do not result in an authentic experience.
Then, too, guided tours tend to herd their charges into "attractions" that they consider to be of mass appeal, often at the bequest of the local tourist authorities — which are, after all, businesses. They seldom venture "off the beaten path."
Plus, except in rare cases, you don't get to choose your travel mates. They may well be great people, or they could be unbearable louts. But whoever they are, you're stuck with them.
Worst of all, you don't always get to see what YOU want to see.
That's why I do what I do.
What I do is explore on my own two feet, poke around promising places, develop a rational approach to them, connecting as much as possible with the locals, and then write and draw maps about it. I've been doing this since 1976, when I launched my Great Trips project, which later morphed into today's Daytrips series of guide books.