it seems to make sense to "insert" a strut into each alignment cell like TeX does.

The problem is even more pronounced if there are more rows.

$
mat(a,b;c,d)mat(x;y)=
x mat(a;c)+y mat(b;d)=
mat(a x+b y;c x+d y)
$

looks like this which doesn't look good

While latex looks like this:

$$ \begin{bmatrix} a & b \\ c & d \end{bmatrix}\begin{bmatrix} x \\ y \end{bmatrix} = x\begin{bmatrix} a \\ c \end{bmatrix} + y\begin{bmatrix} b \\ d \end{bmatrix} = \begin{bmatrix} ax + by \\ cx + dy \end{bmatrix} $$

There are 2 thing different:

1. it looks like there is a minimal height limit in latex: note the [a, c] is not that small in latex
2. typst stretches [ax + by, cx + dy] too high. In latex it's smaller

LaTeX set a minimal height for each matrix cell, it is the same as an invisible (

You may want to try https://typst.app/universe/package/natrix . It somehow "fix"es this bug. The root cause is that LaTeX will pad the height of each matrix cell to a certain minimal height and typst doesn't do it at this moment. I will also try fix this in rust.