Say you’ve written a great song. The lyrics are spectacular, the melody is beautiful, and the chords are divine. People have started asking you how to play it. You could put some time into making a YouTube video (which may never happen), or try something like the band Dinosawh did: Put the chords of the the song into the lyric download.
When you upload your music to Bandcamp, you have a choice of including the lyrics with the digital download. So instead of JUST putting up the lyrics, why not put your chords into the lyric sheet too. This especially works well if you subscribe to the Ramones style of songwriting (3 chords for the whole song). But even if you have more changes than a Jazz fusion band, as long as you can accurately put the changes into the lyrics you’ll be set. This way even is someone wants to learn the song casually they now have all they need.