I disagree, Naruto's art is not as detailed & usually has a lot of unfilled spaces.
My point still stands, you can't compare the starting episodes of a smaller series to a longer series. Ofc the smaller series would have more progression so it'll be easier to get you hooked. OP's pilot episodes skipped out some things from the first chapter too. OP's pacing isn't as slow as you think it is. I don't even know why'd you want a faster pacing as well. It's an adventure, there's no need in rushing it. The pacing is fine and it's reasonable. Also, the amount of content we get each chapter makes up for it as well.
Do you know why OP is so long? It's not only because of their adventure but there's 9 main characters and each of them have their own goals. The scale/size of their goals are bigger than the goals you see from most shonen series.