In my opinion everyone company likes to only benefit from experiences earned elsewhere but never like to provide folks a place to earn the same in their company

In my opinion everyone company likes to only benefit from experiences earned elsewhere but never like to provide folks a place to earn the same in their company. This is very unfortunate, I also see the same issue when someone is trying to even make lateral movement from one expertise to another. (Like backend to front end.) This whole process is a very lazy and unproductive way to hire. I have been thinking about an alternate approach. Where folks spend their own time to learn and build something in the common forum along in a team. Teammates can rate them, code can be available in open repo. That way folks can prove their skill outside their job and job interviews. Like I proved that I can build mobile app once and anyone can recruit me instead of starting from clean slate job interviews every single time.