I recently played the FF1 and FF4 remasters and I have some mixed feelings about them and this series of remasters as a whole.
In general, my expectation of a remaster is for it to be the definitive version of a game, but instead these games feel more like alternative rather than definitive versions. For instance, the redone music, while great, feels like it celebrates the original tracks but isn't really equivalent. The ability to speed through the battles as well as the difficulty being rebalanced and made much easier definitely changes how these games feel.
There is nothing inherently wrong with any of this. These remasters are very enjoyable, and the NES games in particular are just too outdated (imho) so breezing through them with these versions seems like a great way to go through them and probably my preferred way to do so. But there is something in the originals that is not captured here, and this is more apparent in the post-NES games like FF4. I enjoyed the FF4 remaster a lot, but a lot of that was because of how it reminded me of the original. I am of the opinion that the original SNES version (and maybe some of the other remasters - I haven't played them all) has something very significant that is missing here, and this remaster ends up being more of a celebration of the original than a replacement.
There is definitely mobile/casual feel because of this, as described by the poster above.
I think this approach is actually going to be perfect for FF5, which I think of as an unserious game with a lot of fodder to grind through. However, I don't think this approach is going to do it for me, at all, for FF6, which is the first in the series that I consider to be intricately built and "serious." Auto-battle is going to kind of kill some of the feeling that is present when exploring in FF6, especially if the game is made easier. Ideally if they wanted to modernize it, they should have fewer random battles and rebalance all the monsters accordingly, but I know there's no chance of them doing that.