"Until you reach Victory Road" is an interesting stipulation because it eliminates almost every Gym from every game --- no Victory Road can be accessed without obtaining eight Gym Badges, save for one. In Generation III only, Winona can be skipped until the Pokemon League, allowing you to clear Victory Road without ever fighting her.
- You fail Route 23's badge checks in Kanto.
- You can't get past the Reception Gate in Johto.
- Route 120 is impassable without defeating Winona and you can't get to Ever Grande City without Wallace in ORAS.
- You can't get to Celestic Town without the third, fourth, and fifth Badges in Sinnoh.
- There is no flexibility in Gym order in Unova, Kalos, or Galar.
- There are no Gyms in Alola.
- There is no Victory Road in Paldea. Though the Gyms can be challenged in any order and the Pokemon League is visible right after Mesagoza, you won't be allowed into the building until you get the eight official Badges.
If you want to be cheeky, you could say that you can skip the Fighting Dojo in Kanto indefinitely. If you'd like to be even cheekier, you could say that Paldea's "Victory Road" storyline can be commenced without earning a single Gym Badge.