What's with the performance of RelativeLayout / ConstraintLayout?

Question

Android

Hello!
I have one list (RecyclerView) where each item has a rather complex layout (about 40 linearlayouts, textviews, etc.)
It is laid out rather clumsily - LinerLayout and TableLayout are everywhere (this is generally the first layout I have made, do not blame me).
Now I'm limiting it, and now I'm thinking of using RelativeLayout / ConstraintLayout.
Question: are they more productive than a bunch of nested LinearLayouts (in some places with given layout_weight)?
Because now, on older phones, scrolling through the list sometimes slows down, not very noticeable, but not pleasant.

Answer 1

Relative/Constraint will be faster than a bunch of Linears with weights. The weights are important here, as they give a second pass through Linear's children, and negate its simplicity. Nesting is always bad.
In fact, I can express an unpopular opinion - if there is a complex layout inside the Recycler, and this layout is not generalized, but very specific, then it makes sense to think about making it custom. That is, inherit from ViewGroup, add a view (addView) and implement onMeasure/onLayout. Done right, it will be 100% faster than any general purpose layout.
For myself, I deduced a rule of thumb - there is no place for Constraint inside Recycler. Brakes.

Answer 2

The fewer levels of nesting, the higher the performance.
It is more convenient to work with ConstraintLayout and it is faster than RelativeLayout, but not much and not always.