Even FFXIV (my current drug of choice) has limits to what you can do as a solo player. Even the MSQ - the most single-player content in the game - requires you to group up with others every other level and do dungeons. It’s a mostly seamless process with all the duty finder enhancements and roulettes that bring existing players back to the old content, but it’s still there.

The benefit of a clan/guild/free company can’t be understated. They will provide entertainment, support, and access to a set of content that’s otherwise very hard to do.