Group travels have their own pros and cons. In group travel you might meet like minded people, form lifelong friendships, explore together a lot of places. Solo travel is more of you and yourself. You can travel at your own pace, you can plan as you like, see everything in travel from your own perspect. It totally depends on you. You could try both travels once, based on your travel plans and decide which gives you happiness and enjoyment, for travel is more about positivity.
Experience in group tours is altogether different, it’s amazing if the group size is small (less than 20) and other travellers are from the same age group. It may look more expensive but is really worth it.