To someone in ambu gear, or even this new gear, it is.
Someone in ambu gear or this new gear isn't clearing a V20, so it doesn't matter if they can enter it. Letting people enter is intended to build interest among the contingent of folks who have done Sortie or Limbus to get stronger gear but see Odyssey as too difficult or tedious without trying.
"In my day we had to travel through 10 feet of snow for our Ody clears. And were better for it."
I'm not gatekeeping V0 clears. I'm saying that you make the gameplay loop worse by herding everyone straight toward top content and throwing away the stuff they could have worked through. You can get dozens to hundreds of extra hours of playtime that doesn't rely on partying with tryhards if you don't skip all of the older content. If you herd someone straight to Odyssey, that disappears because they will be too strong to find the content challenging or the rewards meaningful.
Some people benefit from that. If you're returning to a group of friends that want to carry you, cool. Getting carried will make you able to participate effectively in that group faster. That isn't everyone. I don't know why this is a hard concept. There is considerable gameplay value in doing older content while not overpowered for it: all of you *** did it when the content was new. If you haven't had fun with any of the content, why even play?