should a tarrasch defence player play the french?

i really like the tarrasch defence against d4 and against e4 i play e5 but the more i look at it the tarrasch defence and the french look so similar in structure. anyone have experience with both of them or any comments on it?

They're only very superficially similar in structure.

Those opening three or so moves have e6, d5, and c5 in many lines of both defenses.

But in the French, this typically leads to a closed central pawn chain, and strategy for the rest of the game will revolve around how both players use this feature.

In the Tarrasch, those same moves typically lead to an IQP structure, and the rest of the game, strategically, then revolves around that.

Something like the King's Indian is a lot more similar to the French in terms of ideas than the Tarrasch.

So there's no "should."

The Tarrasch works nicely if you like to play 1.d4e6, because it limits your opponent's choices while letting you keep open transpositional opportunities within your own repertoire.

The same could be said of the QGD or Dutch.

Or the KID could be said to have simlilar structural qualities.

Or the Slav could be said to have similar "style," in that it stakes a claim in the center, keeps solid but flexible, and aims to counterattack on the queenside when possible.