CodeIgniter 4 Important Features

I think it's a waste of time focusing in compatibility layers unless it's really easy to do.

Let's say I have 100 CI projects. Why do I need to migrate to CI4 all of them? Even if it's easy it will be one more source of trouble. From the old CI projects only a few will justify to migrate probably. And those are probably important projects that need to keep evolving.

Those who don't need to keep evolving will die sooner or later. If you are not developing it in a consistent way why worry about migrate it?

Basically this is my point of view. Some things don't need to evolve and others do. Whatever makes the evolution quicker and better it's very welcome. If compatibility layers and so on will turn CI4 better so be it, if they are only stalling and serving a very small minority of cases then just forget about it and let evolution take control

If you have 100 CI projects, its not 100% needed to move them to CI 4 ASAP. 
You have to separate them to few groups : 
1. Needs to be upgraded. - CI 4 ASAP
2. No point to be upgraded. - No point of CI 4
3. Can wait upgrade.. - CI 4 at good moment in the future

Most important thing will be to start your future projects with CI 4. CI 3 is option too, it wont be killed.

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