I believe the main reasons enriched model category are simpler boils down to:

**Tensoring and co-tensoring by $\Delta[1]$ gives very well behaved path objects and cylinder objects adjoint to each other**

Slightly more generally, (co)tensoring by more general simplicial set gives an explicit construction of the (co)tensorization by spaces, and this also allows to recover the enrichment in spaces using the simplicial hom between cofibrant and fibrant object. But cylinder object plays a very special role in this story.

Having such well behaved cylinders makes the construction of model structure considerably easier, this is very apparent in M.Olschok works (see his theorem 3.16).

In fact I claim the following:

**Theorem:** Let $C$ be a presentable simplicially enriched category. Let $I$ and $J$ be sets of morphism in $C$ such that $J \subset I-Cof$ (or more generally, $J$ are cofibration in the sense below). I'm also assuming* that the domain of every arrow in $I$ and $J$ is cofibrant in the sense below.

Then there is a simplicial combinatorial left semi-model structure on $C$ such that:

The cofibrations are generated by $I$ as a simplicially enriched class of cofibration, i.e. they are generated in the naive sense by the $(\partial \Delta[n] \hookrightarrow \Delta[n]) \widehat{\otimes} I $.

The fibrations *between fibrant objects* are characterized by the right lifting property against the $(\Lambda^k[n] \hookrightarrow \Delta[n] )\widehat{\otimes} I$ and the $(\partial \Delta[n] \hookrightarrow \Delta[n]) \widehat{\otimes} J$.

and Obviously, The trivial fibrations are characterized by the right lifting property against the $(\partial \Delta[n] \hookrightarrow \Delta[n]) \widehat{\otimes} I $.

where $\otimes$ denotes the tensoring by simplicial sets, and $\widehat{\otimes}$ denotes the corresponding corner-product/pushout-product.

This type of theorem makes it incredibly easy to construct simplicial model categories. For example, knowing this it is immediate the left bousfield localization exists, or that left transfer along simplicial adjunction essentially always exists.

The proof of this theorem is not available yet (in preparation, it should be available before in a few month).
Though some very similar result are already available: if you add the assumption that every object in $C$ is cofibrant, then this should follows from Olschok's theorem 3.16 quoted above applied to the cylinder functor given by tensoring by $\Delta[1]$ (maybe with a little bit of work to check that the definition of the class of fibration and cofibration match those I have given). And If you are ok with getting something weaker than a left semi-model structure, this follows from my theorem 3.2.1 here (which produce what I call a "weak model structure").

(Regarding the assumption (*) it can actually be removed, but some modification needs to be made to the statement to keep it correct, and they are a bit to complicated to be explained here... also I don't understand them very well so far)

Another concrete example of interest, which I think could also be somehow attributed to the theorem above, is the construction by Ching & Riehl of a model structure on the category of algebraically cofibrant objects of a Simplicial model category $C$, Quillen equivalent to $C$. Somehow a dual of the well known Nikolaus construction.

This construction uses in an essentially way that the category is simplicial, and more precisely that the the "cofibrant replacement comonad" used to define the category of algebraically cofibrant object is a simplicially enriched monad. This makes the category of cofibrant objects a simplicial category, and makes it easy to put a model structure on it.

In fact, I claim that this result fails without simplicial enrichment. More precisely, if you take $C$ to be the category of simplicial sets, and consider the (non-simplicial) algebraic weak factorization system generated by the $\partial \Delta[n] \hookrightarrow \Delta[n]$ then this category of algebraically cofibrant object has very few model structure, and they are all essentially trivial (their $\infty$-categorical localization are actually posets).

Unfortunately the proof of this last claim rellies on a lot of so far unpublished things so I'm not sure I can explain it on MO.

(This being said Ching & Riehl result might actually be true for any combinatorial model category as soon as one only wants a right semi-model structure on the category of algebraically cofibrant objects... but I don't know a proof of this)

A final remark: I don't think these things are specifically about "simplicial model category", it is more about the difference between enriched model categories on non-enriched ones. You can do similar construction for essentially any kind of enrichment.