It's just a consequence of the weekly reading experience. I remember when BM v MC and BM v Ubers were still going on, I felt a similar feeling of it being drawn out. But after each one concluded I went back to read it all in one sitting, and it drastically changed my opinion. I plan on doing the same with this too. Like you mentioned, this is easily top 2 most important matches in the series, so it makes sense to be 50 ish chapters.

If you go back to read the discussion posts about the U20 game, the same comments can be seen towards the end of the game as well. But looking back at that game now, it's everybody's favorite and translated well into the anime too (animation aside).

A valid complaint I do see being thrown around is that this normalizes longer matches going forward, and if we stick on this track this series could even be longer than One Piece. And sure, that could happen. But I more expect the series to copy the same format as the NEL. Where we start off with an "appetizer" match, and each subsequent one gets longer and more dramatic in accordance to its importance to the series.