I’m going to take a risk and guess that you’re American or perhaps European.
The acting, editing, sets, writing, and direction of Lee’s first two films were under Golden Harvest, part of a new wave of Hong Kong film companies that had been given greater artistic control over their products. Their predecessors were companies like the Shaw Brothers who had made dozens of hits churning out “week’s worth wonders” like Master of the Flying Guillotine and tales of flying sword-wielding wizards and demons. A lot of those were little more than martial scenes a director managed to capture on film that were then left to other production crews to string together into some kind of a semi-coherent tale. They were, in that sense, the predecessors to the Canon (Golan/Globus) Films products that came later.
Bruce’s early experiences working for the Hong Kong Film companies occurred during the transition from Shaw-style production approaches to Chow (Golden Harvest) -style approaches – which is perhaps to say, “Let’s build a story that leads up to a fight.”
So while The Big Boss may not seem like great cinema, you can compare it to something like Master of the Flying Guillotine and see a considerably more coherent (and possibly more compelling) story. I realize that still doesn’t compliment The Big Boss very much.
Nor is it much of a compliment to say Fist of Fury was somewhat better. While it drew on an incident that was well-known to the Chinese (particularly to Chinese Martial Artists – q.v. the end of Fearless and the starting premise of Fist of Legend) and was a cathartic vent for long-suppressed frustrations going back to China’s first major encounters with Western powers, it was still created first and foremost for a Chinese audience with any success in the West being an added/unexpected bonus.
When Lee created his own production company and wrote Way of the Dragon, he wrote the tale to fit the planned fights. But Bruce’s experience was from television (which in the 60’s was more about a situation with episodes and less about character growth and story arcs) and the Hong Kong 7-day wonders (which were mostly about finding excuses for fight scenes – see above). And while, as you note, the pairing of Lee and Norris at the Coliseum seems grandiose and was pivotal in launching the latter’s film career, it really isn’t much more than another spectacle that the director wanted to shoot and fit into his film somehow. In this case, the Director and main character were both Lee.
Bruce then turned his attention to his next project.
In contrast, when Warner Brothers decided they wanted to capitalize on (i.e. try getting a piece of the market) the kung fu craze, they made a wise choice in sending Lee’s friend and former boss to ask Lee to be the star. Enter the Dragon was an interruption to Lee’s planned magnum opus, but the offer was good and he needed the money in order to finance his new production company and project. That was quite a fortunate situation for everyone.
Being an American cinematic company, Warner Brothers worked in a different manner than the Hong Kong (particularly the martial arts flick) industry. Furthermore, the film writers worked differently from the television writers: They started with a framework and a plot, built in side-stories, added excuses for fights, and then choreographed and filmed them. The point is that Enter the Dragon is a movie that fits American sensibilities about how a movie should flow largely because it was written by American writers for an American production company to sell to American audiences. And this is why I’m guessing you’re American.
Game of Death, of course, was an unfinished and only partially-filmed script which ghoulish entities tried to salvage simply to squeeze more funds out of the fan base. I seriously doubt many of the tricks they played would be possible under modern legal conditions in the industry. Nevertheless, it was done and the result is something of a Frankenstein’s Monster of real and look-similar actors, original film, recycled footage, original story, and a plot that went way off-track from what Lee originally intended and the point(s) he was trying to convey. No wonder it seems like a mess. The only slight saving-grace was that, because the people involved knew they were exploiting a fad, they were willing to provide high-quality Hollywood production values (at the time) to make the final product as slick and presentable as possible. It looks like a high-quality film because the equipment and techniques were high-quality and, IF you can just sit back and try to enjoy/follow the story line, it’s about on-par with Way of the Dragon and still better than the Golden Harvest products.
Last, but not least, the Wachowski Brothers (famous for their spectacular choreography for The Matrix) would not have achieved their fame if not influenced by the predecessors in Shaw, Chow, Lee, and others.
[a former student of several martial arts and teacher of two]
We who achieve greatness do so by standing on the shoulders of those who came before us.
–Albert Einstein (I think…)
 Marketed in the West as Return of the Dragon
 For the closest approximation of his plan, see Cross of Iron (1978) – but don’t watch it expecting superb martial arts mastery…