I do not hope Lance fails. I expect Lance to fail based on what you said plus the other thing that was unsaid. As you pointed out a great organization looked at him and said thought they were better off with the last pick in the draft and Sam Darnold. Now how good Purdy is is a debatable point but at this point we know how good Darnold is, or in this case is not. That tells the level that Lance is at now, or at least was at the start of the season. Combine that with the fact that as of next season it will have been 5 years since Lance played more than 2 full games at any level. The last time he will have played meaningful minutes is the one year of college tape on him before he sat out the last year of his college career. So he has to overcome 2 separate issues: having barely played football in half a decade and having to elevate himself from a quarterback who is not in the top 50 to being in the top 10-15. Both of those are very rare things to overcome individually but would be incredibly unlikely to see happen in tandem. Would it be fun to see happen? Sure, but it is incredibly unlikely.
Meanwhile if a top 10-15 QB appears in FA, or if they Cowboys are drafting in the top 5 and can take a shot at one, then I would not mind going for it but barring that then yes I am satisfied having someone for whom every offseason the professional GMs, Scouts, and Coaches all vote as top 10-15.