It's still progress and good progress at that. It might not matter to you, and that's fine, it doesn't make it any less of progress or any less of what matters in one way or another to many others.
i believe the person you were referring to was refuting an argument that it was so much more noticeably faster that speed alone justified the upgrade.
yes it is much faster hardware on spec sheets and benchmarking tools, but i agree from trying out in store, it is not really that noticeable in general use. the most meaningful gain is likely from ram if you regularly like to keep lots of tabs open.
i'm sure like all s-series phones, it *will* become noticeable in its relative longevity. But if you're the type who's already trading in a 6 for a 6s for perceived performance gains, you'll never last that long with it anyway.
i'd go even further and say all the hardware speed in the world is wasted on how clunky iOS tends to feel these days. even the beastly iPad pro i tried in the store still felt like it stuttered on animations.
i'll give you this, i went into a pop-up samsung store, and i couldn't do a single thing on their display devices without stuff crashing all over the place.
the industry trend of late seems to be to push out as many features as possible at the expense of stability and polish, and hoping raw hardware gains compensate for half-baked software. i guess its a viable model, but i'll still mourn for what we lost in the process.