It has arcs for sure. I just agreed with the "not really" sentiment because of a private nitpick I have with the series. I look at MHA's contemporaries, and it's pretty damn easy to know where the arcs begin and end. Chunin Exam arc. Soul Society arc. Enies Lobby arc. Chimera Ant arc. Etc, etc.
They're visually distinct arcs. I have a much easier time of figuring out once said arc has begun due to their visual presentation differing from whatever the last arc was. Also it helps that their names tend to stand out as well.
Meanwhile MHA has been trickier for me, I feel like it's lacking in visual variety. It just feels like we're in this city (and school by extension) all the time. And yea, we've gone places (the school festival, the camp), the majority of it just feels so... samey. It feels like it all just blends together. Like one of the arcs is legit called the Rescue Bakugou arc by the fandom. It just sounds so damn awkward to say aloud. Now, this could be partly because I might just not ultimately all that attentive as I should be, but the feeling persists regardless.
When people talk about their favorite arcs in this series, all I can really remember is like the individual moments, stuff like All Might v. All for One for example. But someone asked me to describe the settings of these arcs, I'd admittedly be at a loss for a lot of them.
Even with this arc, it is indisputably an arc, I know how said arc ended (albeit because the last chapter literally said as much), but the arc pretty much just had us in that basement.
So yea, it has arcs. It does have stuff like villains and such to help out a little in labeling them, and yet... I still feel like this anyways. I dunno, it's kind of hard to articulate properly, but basically I wish MHA was more adventurous with its settings.
