In my experience such "lightweight" distros, over time, accumulate expanded functionality/compatibility/surface area and inevitably/gradually become "heavier".
Then the community complains "X" is too heavy, we need a lightweight system! and the cycle repeats itself.
Which is why ArchLinux is so nice that it doesn't suffer from this type of growth by nature of its design. You can very easily layer lightweight frontends on a very reliable core.
Then the community complains "X" is too heavy, we need a lightweight system! and the cycle repeats itself.