I'll add on to this too, as someone who largely agrees!
I work for a company that has several mid-sized PHP projects. Some started life back with early PHP5 - eg 5.1.
The biggest reason I don't like slim frameworks is that they make every project unique.
Projects that start small rarely stay small, and if every project gets to pick it's own router, it's own method of doing CLI commands, it's own ORM, it's own messaging/queue stack, etc - then well intentioned decisions create a ton of variety in projects over time and it makes it very hard for people to jump from project to project. It also makes upgrades a mammoth task.
We tested Slim, Laravel & Symfony and settled on Symfony.
We found huge advantages in using a framework that can be installed piece-by-piece as you need it, but where the pieces are the same every time & consistently designed, and where the whole thing is designed to be upgraded in one go.
Going with Symfony has been a genuine productivity improvement for us - every project follows the same basic structure, we try to follow Symfony best practices, we try to minimise tons of external dependencies. It makes maintenance much much easier, and makes something like 'hey, we really should be processing this async in the background' an easy step - just install symfony/messenger, rather than evaluating different options, etc.
edit: we didn't go for Laravel because Eloquent really didn't compare well to Doctrine, and the amount of hard to debug 'magic' was much worse for us than Symfony.