Comment by nh2

The point was that most of the shown software is optional, and you can check how much selecting those parts you care about sum up to.

To provide "conclusive proof" that it's possible to run a 128 MB Linux system.

For example, if you remove (or configure smaller memory use for) journald, the Amazon daemon, oomd, timesyncd, you are already at around 128 MB userspace, with more that can be removed if desired.

And this is on a distro that is not at all designed to be minimal in memory usage.

How much cache is good depends entirely on what you want the system to do.