Let $k$ be a field and $\operatorname{DM}_{gm}(k)_{\mathbb Q}$ the ∞-category of rational geometric motives over $k$. A mixed Weil cohomology theory induces a symmetric monoidal exact functor

$$
R: \operatorname{DM}_{gm}(k)_{\mathbb Q} \to D_c(\mathbb Q),
$$

where $D_c(\mathbb Q)$ are the compact=dualizable objects in the derived ∞-category of $\mathbb Q$.
For abstract reasons, there exists a best possible commutative Hopf algebra $H$ in $D(\mathbb Q)$ such that, if $G=\operatorname{Spec}(H)$, then $R$ lifts to

$$
\tilde R: \operatorname{DM}_{gm}(k)_{\mathbb Q} \to \operatorname{Rep}_{D_c(\mathbb Q)}(G).
$$

This general construction can be found in this paper by Iwanari.
As you know, Ayoub has also constructed $H$, but only in the homotopy category of $D(\mathbb Q)$, which is not enough to define $\tilde R$.

Let me now assume that $k\subset \mathbb C$ and that $R$ is the Betti realization. Ayoub then proves that $H$ is connective, so that $\tau_{\leq 0}H$ is a Hopf algebra in rational vector spaces. If $G^{cl}=\operatorname{Spec}(\tau_{\leq 0}H)$, we then have a closed immersion $i\colon G^{cl}\hookrightarrow G$, whence

$$
i^*\circ \tilde R: \operatorname{DM}_{gm}(k)_{\mathbb Q} \to \operatorname{Rep}_{D_c(\mathbb Q)}(G^{cl}).
$$

Choudhury and Gallauer Alves de Souza proved that the group scheme $G^{cl}$ is isomorphic to Nori's motivic Galois group.

The strongest conjecture one can make here is that $i^*\circ\tilde R$ is an equivalence of ∞-categories. This conjecture is equivalent to the conjunction of two conjectures: $\tilde R$ is an equivalence, and $G^{cl}=G$. It also clearly implies the conservativity conjecture (that $R$ is conservative) and the existence of the motivic $t$-structure. Conversely, the existence of a $t$-structure such that $R$ is $t$-exact implies that $G^{cl}=G$. The conservativity of $R$ together with the existence of a suitable $t$-structure should imply that $\tilde R$ is an equivalence, but I cannot find an applicable reference at the moment.