Many people (?most) disagree; and some have succeeded in editing them together to make a convincing whole.
Episode 26; Shinji confronts his issues, realises that his perception of himself is not the only truth, overcomes his issues and lives happily ever after within the Sea of LCL.
It is not clear that he remains within instrumentality; indeed that would not be a good message for the series to end on (that the solution to your problems is to escape from this world).
and finally wakes up on a beach and tries to murder Asuka again.
And stops when Asuka shows him a sign of kindness or empathy - there is a future after all, however bad things may have got (a much more positive message than your interpretation of episode 26 in my view).
a retelling of the story without the darkness of mental health issues weighing him down.
Though making the third film broke him again...
For this reason, I'm hopeful, that when all is said and done in 3.0+1.0, that Rebuild will stand alone from the series
In my view it already does; and sequel theory is just a desperate way of trying to deny that fact.