[MagnumOpus]

Agreed with the latter, don't agree with the former.

Tinkering gives you out-of-domain experience which subtly improves the decisions you take - both architecturally and organisationally. It gives you at least a bit of an insight of what the right tool for the job might be even if it is outside your domain.

If that tinkering is in hacking IT security, and you do CRUD app development (or project management) for a living, your app might just coincidentally avoid SQL injections or obvious buffer overflow errors. If that tinkering is in image recognition and machine learning and you are a business manager, you just might know the difference between "feasible" and "impossible" AI projects (avoiding this XKCD situation: https://xkcd.com/1425/).

Obviously you will also avoid these if you have actual professional experience in IT security or AI - but very few actually can get involved in a dozen fields professionally at once.

[watwut]

The thing is, if it is your job to do crud applications, then having a look at security development at least once a year is a part of job. And at that point, you will learn about sql injection if it is a new thing. If sql injection was something known for 10 years, then you would learn it in the process of learning crud.

All that assuming you take work seriously.

I think that when young people spend their time doing something, it says somethi nd good about them and their environment. However, you can learn the things they learned later on if you have aptitude and study the topic seriously.