I said "speed" not dimensional travel
Let me give you an example, whiz could travel through universe 7 and 8 (iirc) through sheer speed. Thats an anti-feat.
Using portals/dimensional travel/teleportation or any hax, is not speed.
Eh, no, not how realm travel in God of War works. At all.
You physically cannot travel between the realms without using the Realm Travel Room, nor can you acces the void (The Realm Between the Realms) from said realms without using the Mystic Gates (The Mystic Gates mostly serve as a fast travel route between locations situated on the same realm, but to do so, it also grants you access to the Realm Between the Realms, which is our void).
The Valkyries can do both simultaneously because they have complete mastery over the Bifrost energy which gives them the ability to open the gateways into the void, but they still need to physically travel the void in its entirety before reaching the other realm and opening a gateway into that using their magical Bifrost abilities. Keep in mind that the Bifrost is also used to operate the Realm Travel Room.
And then, you cannot travel the physical space of the void without the Unity Stone, since not even the Gods are allowed to stray from the path (They will get erased from existence otherwise), but weirdly enough the Valkyries are granted that because of their Bifrost powers. Tyr however, followed his own path using the Unity Stone, which not only has the same abilities as the Bifrost, but also allows inter-pantheon travel.
So practically no matter the method, some sort of dimensional travel/portal is still involved?
Not sure how to word it honestly but to a degree, yes.
Want to travel from realm to realm? Can't do that physically, need the Realm Travel Room powered by the Bifrost, or you need complete mastery of the Bifrost itself (This one opens the gateway to the Realm Between the Realms directly without needing Tyr's Temple at all, but you still have to physically cross the void, the full length, between the universes, before you reach the other realm to be able to open gateways into it), or the Unity Stone.
Want to enter the Void AKA the Realm Between the Realms? Can't do that physically either, you need the Mystic Gates, the Bifrost energy, or the Unity Stone.
Want to travel the empty space of the Realm Between the Realms without getting erased? You need the Unity Stone or Bifrost powers.
No Bifrost or Unity Stone? No Realm Travel or Pantheon Travel, and you can't enter the realms from the void physically without the Bifrost Powers or Mystic Gates or Realm Tower Doors either.