I have deffinately improved, but most of this improvement is due to better music, arrangement and production. Obviously a small amount is now due to lyric but i have noticed that each time i go back to the archives to rework an old song the lyric doesnt get changed much but the musi is altered a lot. Keys, to better match my vocal, structure to make it more accesible and get the hook in earlier and shorten the song.
But one thing i have noticed, is that i write, or kkep might be a better idea, less crap. When i first started out some of ideas, both lyrical and musical were not great but i always took them thru to completion. Now i am much more discerning so i am getting more consistent results.