And right here is your major mistake:...
Tired of reading a slice of life manga that is merely 15 pages a chapter.
My answer to all the criticisms stated can really be summed up by the same point.
After decades of being serialized, it's easy for some readers, especially those who are younger than the series itself, to forget much of what came before, both in substance and in style. This manga is not what you remember, or expect. That's it.
This series has not changed. Ippo was not someone who took unnecessary hits. Readers imagine some kind of paradigm where a boxer becomes champion without taking any considerable hit, that was a realm only someone with superlative talent like Ricardo exists in. In fact Ippo often took extra hits when he forgot coach's instructions or advice. Sometimes Kamogawa tells him to then power through, but only because Ippo refuses to give up in later rounds and it's the only that way or throwing in the towel. Often the only thing preventing Kamogawa throwing in the towel was how fast Ippo won from those situations. IPPO IS THE PROBLEM, if anything. He has never shown his analytical ability in a match itself to a substantial degree, and his ability outside the ring is actually very, very recent, only appearing partway in part 2 of the series.
Readers imagine some manga where it was not 90% spice of life and humor, and 10% spars and bouts. Whether Ippo is active now or not in the narrative, doesn't change anything except who is in the ring once it comes time. But we still get the same excitement. This is not even the longest super arc the series has been in, it's the third and still the shortest of the three.
If Ippo specifically not being in the ring is a problem for readers, then they've also forgotten that one major strength of the manga is how it builds Ippo up through the other fighters that make up the story, by fleshing them out. It's actually most disappointing to get fighters who are caricatures and simply explained, as was common early on in the manga. Morikawa has certainly changed, become more professional, and learned that the cast of characters is what many come back forz that makes this manga popular.
And finally, readers have forgotten the simple fact that this manga still runs. Still draws sales. Still gets a pass by the editors. The series sales dipped after Ippo's retirement arc started, but became steady ever since, indicating that the series long term dedicated fans are enjoying it. The series still gets into the top 10~20 weekly sales consistently and sells through a consistent number of volumes, as it's done pre-retirement. Morikawa is writing something that is popular, that is something his magazine and volume buying readers want to read. Some other readers just might not realize they aren't included.
In fact let me turn that back on itself. Morikawa could write a story more to the liking of many readers here. He can write what some fans think they want, rather than what many others actually read, and more importantly, buy. Morikawa is a professional right? So what's he going to do?
And I'll only just repeat again that this hardly looks like what constitutes "minimum work" for a mangaka. It is definitely not this. I don't see assistant credits on the cover page. And again, writing a story that you think is slow, lacks substance or you simply don't like, isn't less work for the author. This is not school essay writing where a kid spends more than half the time thinking up a plot for a 150 word assignment.
I didn't really want to throw this card, but I've got like 50+ odd volumes of this series on my shelf. At least 20 are from the early days, and the rest from the more recent arcs. I can pick through them and not see any of the stuff you guys talk about, like Ippo's supposed pre-existing talent at analysis, or this lack of 15 pages of SoL.