Tuchel did fuck it up. Don't know about sacking him, but when you're hired precisely to be good at the big moment and you fuck up the big moment, it's fair to say you didn't fulfil the brief.
And I really don't have a huuuge irrational attachment to English success, I have a semidetached relationship at best to the England national teams in every sport except cricket, and so I don't think I speak with overmuch bias or anything when I say that England, with these players and the squad available, should at least aspire to going out with a bit more dignity and honour than with their shoes drenched in a puddle of their own making.