On the other hand, my custom made site that I designed without a framework still today works even with PHP8.3 . Sure I had to do some minor compatibility changes.
I've been ranting about all the dogma in the PHP world back in 2010-2013. Most of it didn't make any sense. It added complexity and de development time to gain what exactly? OO fetishism. Did you know that to this day Symfony kernel copies all the request variables from the request context (aka $_GET, etc...) into memory so it can access it in a OO fashion. The request context in PHP never changes FFS! Using Symfony you have a largely reduced number of concurrent requests possible, about factor 4 vs plain PHP. Anyhow... rant over