Totally understandable. It took me years and years to get used to and to remember how it even functions (was it 2 or 3 angled brackets?). Just to be clear, this was not a critique or attack (as you defended your way of doing :D), I just wanted to share another possibility.

Just a little note, that you can use the Bash “<<< heredoc” sed 's/l/x/g' <<< 'hello' to read stdin, instead using echo for this job. The reason is, this is more pure and direct without any alteration compared to processing with echo.

How is this Linux related?