It seems weird that the awesomeness of my project ideas would have exponential growth over time

Yes, but I wouldn't totally discount this factor. When I look at the history of my projects for the past few years I think the more recent ones do tend to pack a bigger punch in objectively measurable ways. I can see progress from "publish obscure articles cited by no-one in local, low-prestige journals" to "publish articles of interest to a reasonable number of people in the same journals, get cited a bit" to "publish articles in international, medium-prestige journals".

If it looks to you like you're grappling with bigger and better stuff as time goes on I doubt that is entirely an illusion.