Apparently, people travel in order to experience the local history and culture as well as their customs, and relax themselves. There're various ways for us to go for a trip. Nevertheless, it's hard to say that traveling in group with a tour guide is better than free tour.
Traveling with an organized group is much more convenient. The only thing you need to do is to find a reliable travel agency. There'll be a shuttle bus to pick you up and there's nothing to worry about. It's safe and secure because there're professional tour guides and drivers who are familiar with the local attractions and the route of journey. The travel expenses are specific. There won't be any extra fees if you don't have special needs. It saves plenty of time. The moment you get on the bus, you can have a sleep. And You can take photos and post them in your moments as soon as you get off the bus. If you're well-off, high-end personalized service is a good choice as well.
Whereas there're some disadvantages of traveling in group. The schedule is unchangeable. You'll hurry to visit the attractions the whole day. Usually the tour guide will stay for a while in some shopping spots. It's a waste of time and the products are costly. What's worse, you almost have no chance to come into contact with the locals and enjoy tasty food.
Free tour, speaking of which, the majority of people would like it, I assume. One of the biggest advantages is that the schedule is flexible. You can do whatever you like during the journey. Choosing a scenic spot that you really like, for instance. You can walk along a sandy beach and feel the breeze touching your face instead of being in a rush, that's called a tour. You may even take part in the Water-splashing Festival with the Dai in Yunnan. It must be fun. With regard to accommodation, you can stay in homestay and try some local flavors.
However, it's essential to make tons of preparations for a free tour, such as booking a round-trip ticket, hotels, attractions, restaurants, transportation, unexpected situations, etc. You have to think about these.
From my perspective, if you're a doer and capable of making a thoughtful plan, it's better for you to choose free tour. On the contrary, if you're not experienced in traveling and not willing to seek for travel guides, traveling in group led by a tour guide is much more suitable for you.