I know it is a different kind of exploration (I forgot to say that), but it is still exploration. Plus, I see Frontiers' as a different take, same result of fun for exploration. This is not like the Legend of Zelda: Breath of the Wild, too, for at least you have speed with Sonic. Speed is probably the number one thing Sonic is known for; sure, the exploration in the 2D games used more so momentum based physics, but Frontiers still has speed (which is a part of momentum) nonetheless with exploration. I would say that exploration and speed can still make a Sonic game fun, no matter what kind of exploration is.
Anyway, maybe you are just not used to it, especially the dash pads and jump pads as you mentioned. I would not say they would take Sonic miles from one place (miles to me is an exaggeration), and you just have to learn to deal with these kinds of things, like some things in any game. (Not all like if the physics are bad, but still). I mean, I did see some not like the mashup with Sonic elements in an open world, all from another place; however, it still works, or works well enough that it did get positive reception, nonetheless.
As for me, I really don't see the problem with Sonic Frontiers' style of exploration. It can be argued that a Sonic game can be incomplete when it does not have speed AND exploration, and I say the exploration for Sonic Frontiers, coupled with the speed in it, is rather fun. What else could you want from it?