You talk about this game? I read about it for a whole half minute and believe that your situation is not comparable.
It is like asking, why you can't cross the sea in a barrel, because barrels float and ocean liners float too and they can cross the ocean.
The floating is not the cause, it is just a helpful thing. Same as it is not the early access that gives success. Same as having a demo version gives not success. But take away the floating or the demo version, and you gonna have a hard time.
Early access is a money grab with usefull side effects. You either satisfy demand for a game that was advertised or you use it for extended beta testing and to get some money. Also, free marketing. And releasing in "early access" gives excuse to have even more bugs in a game that people would be angry about, if it were regular release. And that palworld marketed for a about three years before going early access and we talk about a game with a budget of around 10 million dollars.
The play time is another such thing. Just because you inflate your play time to 15 hours does not make a game successful. But on the other hand, very short games are deemed by some players not worth the purchase. But it depends a lot on the genre. For a crafting game, 15 hours is a bit on the low end. Those can easily have 100+ hours of play time. And if you do it wrong, people might detest the grinding.
Now, there is a bit of wisdom in the play time. But you need to view it backwards. If you managed to make a game that people want to play for 10+ hours, that is probably a good game and might have commerical success. So if you only look at the commercially successful games, you will notice that there are many games with a play time of 10-20 hours - and might jump to the conclusion that the play time is a cause. It is not. It is an effect or maybe only a side effect. Because you do not take into account all the other games that have this play time and are unsuccessful.
And that is my conclusion about all this. There is survivor bias at work. We notice the games that are successful and see things they have in common, but that statistic will not tell us, what is cause, what is effect, what is correlation. And the marketing budget is often forgotten.