Both formats make it easier to read and access more devices. Just for myself I also most always have my phone but 50 year old eyes can’t easily read type on a Letter/A4 or Statement/A5 PDF.
There are also notebook apps like Obsidian that use Markdown. I keep a collection of MD RPG files, rules, random tables, adventures and notes.
And I sometimes make printed notebooks for the table like Fieldnotes 5e notebooks. Having the rules already in MD saves a lot of time.