I hate web dev. Mainly because of JavaScript.

Actually, only because of JavaScript.

I have run teams in both styles, and I can confidently say that mixed discipline is better in delivery.

The con would be that I, as a manager, had to have a solid cross discipline knowledge, which I didn’t at the beginning.

It’s a living hell. I got into programming to write code and solve problems. As a manager I have 4-5 hours of meeting a day, at least, not always at sociable times. And then you have to deal with all your teams personal problems, office politics, management. I’m still expected to get jira tickets done too.

Don’t do it, unless you really want to go into management. There are better paths.

I have had very similar experiences to this. The worst was when we did a hackathon for a day to prototype some people’s ideas. Sales were selling the ideas as features the following week.