I think it's ok that you overestimate your own ability because I'd rather have 1 really really good song better than anything I've ever seen before than 10 mediocre songs that were intended to be more than they were
yes but the problem is, if you plan on making 1 thing to be the best, it very often curses that thing. where as if you do many things, you tend to get a lot better at it, and it is increasingly likely that certain ones will shine as 'best', and it would probably actually be different ones for different people. for example, when i'm choosing which song to do, i usually find myself totally paralyzed because i'm afraid it will be the only one. the only way i've ever been able to convince myself to feel comfortable picking a song is to absolutely promise myself that there will be many many songs. if any song attempts to be the only song it will find itself extremely cursed