Earlier quoted context omitted.
Pro tip: don't put your stuff in your $HOME directory. $HOME is for applications to pollute. Put your stuff literally anywhere else.
I can’t tell if this is sarcasm or not. $HOME is the one directory which belongs to the user. In some cases, it might even be encrypted with a user-owned key. I can’t imagine being comfortable putting my files anywhere _outside_ of the home directory. That feels like going back to the DOS / Win3.x days where hard drives were the wild west.
I don't want to have all this `.cache` and similar stuff to take up my expensive backup storage, nor do I want to waste time cleaning up after all the applications that create/expect files in `$HOME` or think this a sensible place to put executable files. I don't want arbitrary applications (heard of tracker?) to start indexing my files and waste CPU on that etc.
Also I don't believe in /home being portable across multiple Linux distributions because e.g. different application versions might require config files to be migrated. Hence I opt for `/data` that can safely be shared across multiple systems because it contains actual data and not some OS-related state files.
On multi-user systems, the `/data` approach doesn't scale. There, I prefer to do just as boomboomsubban writes: I create a subdirectory in $HOME (usually, I call it `wd`, the "working directory") and treat that like my local `/data/main`. For large/temporary files (e.g. application downloads etc.) I add a `$HOME/large` directory to keep the `wd` reasonably small in such cases such that I can again include it in backups without having to worry about the size.
YMMV