For large projects, using a framework and writing code the way the framework wants you to means that it's much easier to get new team members up to speed, meaning they contribute sooner and with less draw on other team members to teach them the nuances of your weird custom stack.
For small projects, and side projects especially, you can't/don't want to lose steam in analysis paralysis deciding on every little library and thing you want to use. Just pick up the framework that has made most of those decisions for you and focus on the business logic.
Rails nails this. Laravel is pretty good at this. Lots of others do this too (rails and laravel are where I spend my time). Sure, they might not be "exciting" but they are productive, and that, to me, is most important.