It's a bit like the <center> tag. A codebase that's littered with stuff like "InlineStack" is harder to work with and parse because the resulting div soup still requires extra styling, which is now both markup and CSS.
Compare the following:
<Stack gap={2} direction="row">
<Box>
<Avatar />
</Box>
<Box>
<Button />
</Box>
</Stack>
-----
<MyCustomWrapper>
<InnerChild>
<Avatar>
</InnerChild>
<InnerChild>
<Button />
</InnerChild>
</MyCustomWrapper> <div className=“flex gap-2”>
<Button/>
<Avatar/>
<\div>
Then just apply the box styles using *: selector or directly in the component