It is not whataboutery, it is about comparing like with like
No it isn't.
When you voted brexit on the ballot paper you could have been voting for anyone of about 15 different versions of brexit, potentially radically different. For example Norway, Norway-, Canada, Canada+, Turkey, No deal, BINO, etc, etc.
When you voted remain, you were clear you were voting for one thing (stay on current terms).
What happens in 20 years time is neither here nor there for either position. Leaving the EU could look totally different in 20 years time too. None of us have a crystal ball.
The point is that the terms of leaving were not clear at the time of the vote, but the terms of remaining actually were. This is not surprising as remain was by far the simpler option.