As far as Japanese media is concerned, I have yet to see a case where 'chunibyou' actually accounts to a character being an actual delusional, rather than an elaborate make believe or just pretending (look at Okabe).
It may become an escape mechanism, but so can many other things. Without even looking at the most notorious examples of alcoholism and drugs, there's: gaming, reading, watching, etc. So many 'fun' things can become an escape mechanism if done out of proportion. I'd say so is the case of chuunibyou. It isn't an inherently 'bad' thing.
And such, I can't say I condone to throwing all of Rikka's chunibyou out of the window. And deep down, a part of Yuuta also thinks so, but he is now deeply conscious about how 'irresponsible' for him to say that to Rikka. OTOH, Rikka also knows she shouldn't cold turkey her habits, but she needs Yuuta to confirm to that (as Sanae alluded). And so we arrive at the current ぎこちない situation, the hooks they try to tie keeps missing each other. I think there is only one way the narrative could go from here (because there is only one that keeps recurring throughout different series I could think of that leads to a somewhat happy ending).
To quote Keima, "I can already see the ending!"
