I think a better measure really is lines of code. A comparison with react is _very unfair to laravel/rails_, with laravel being a full-featured framework, and yet react is still much worse:
laravel/framework:
no-dev-deps: 307,405 lines of PHP (36MB)
all-deps: 535,383 lines of PHP (58MB)
react (stock create-react-app)[1]
all-deps: 1,570,720 lines of Javascript + 96417 lines of typescript (348MB)
rails (rails new app):
(no-dev-deps): 264123 lines of Ruby + 23614 lines of C + 17009 lines of JS (55MB)
(all-deps): 332083 lines of Ruby + 23614 lines of C + 18055 lines of JS (54MB)
The point is that Composer packages are far from being that granular, we have less dependencies by literally order of magnitude.