How to handle personal stress caused by utterly incompetent and lazy co-workers?

I’ve worked in Software Development teams my entire career and I’ve come to realize the spectrum of skill-sets is utterly staggering. Over the years I’ve managed to adapt my in-office behavior to handle utterly incompetent and lazy people.

The way I handle it is to simply cap my anger and frustration, but I find myself going home and venting my anger in the form of complaining to my family and friends, but this is not healthy to me nor my family/friends.

How do I handle personal stress caused by utterly incompetent and lazy co-workers?

Optional info below:

In my younger years, I naively believed incompetent/lazy people didn’t cut it in the software industry for long. I disappointingly found that preferential treatment, nepotism, and just plain self-interest on the part of managers seem to undermine this natural filtering of idiots from the software engineering industry. Thus, it seems I must learn to deal with them.

I have endless patience for people who are junior and ask numerous questions, but I don’t seem to know how to handle stress caused by the utterly incompetent and lazy people that don’t apply themselves.