Forgot that after the corona break we exactly tried 3412 like you've pointed out above? And it was nowhere near as stable and effective as it was when we switched to 352 for the last part of the season.
So no. It couldn't have been. Unless you think not conceding for like 7 games straight, winning against Atalanta and Napoli in such a style, something many many people were shocked was a bad outcome?
You are insane.
https://www.football-lineups.com/match/323175/
https://www.football-lineups.com/match/323194/
https://www.football-lineups.com/match/323205/
Three first games. In all Eriksen started.
The only one revising history is you because you are as biased as they get. Conte did his all to try to incorporate Eriksen after the break. He even fucking changed the formation for him, as he couldn't work in 352 as one of the side midfielders. It was only after a few games where Conte saw it doesn't really work gameplay wise as we were too exposed that he ditched him and later in the season he switched to 352 altogether, especially in Europa League.
It's people like you who forget things like that because you already made your mind and the reality must match it, not the other way around.