Nope, not the case. The Turkish economy is very strong, and the workforce is young and energetic. If Turkey joined the EU, the aging European population and the crumbling economies of Greece, Italy and Spain would be a drag on the growth of the Turkish economy.
Essentially, the only major benefit EU membership would give Turks is the ability to freely travel around Europe without needing passport visas.
While workforce being young and energetic is helpful, it's not the sole reason of someone's economy being strong. I'm pretty sure most African countries have way younger population.
It's not like Turks already don't go to Germany to work.
The Turkish economy isn't going to remain strong if they keep doing stupid things like this. The free flow of information is vital to the growth and sustaining of an economy.
I think Erdogan sees China as a model for the future, as a provider of cheap labor. So, Turkey doesn't need to intellectually integrate with the rest of the world.
That's actually our greatest hope. If foreign investment dries up as a result of political instability, enough people might stop voting for him that he might be outed in a semi-democratic process (if he doesn't rig the elections as usual, that is). Otherwise, things will end in violence.
There's a big difference between being able to travel to a country without a visa, and being able to freely emigrate there, which is what EU membership provides. Turkey's economy may be growing, but the GDP per capita is a quarter that of wealthier countries like the UK or Germany.
Joining the EU would also give Turkey a seat at the table. Turkey has a large population, and would therefore get a large representation at the European Parliament.
Essentially, the only major benefit EU membership would give Turks is the ability to freely travel around Europe without needing passport visas.