[hyperbole]

What is your definition of a 'team', is it a 2 pizza scrum team, is it your PD organization? In the real world team members have varying levels of context & product understanding - a tech lead should be the person with a firm enough grasp of a functional area to help make a decision, and that person doesn't always need to be a member of the team, nor is it true that the tech lead needs to make the decision because normally decisions are a collection of trade-offs - and the role should be to guide the team to the correct one, i.e. we were thinking of doing this, response: if you do that did you think of this consequence, or perhaps you should consider doing this instead...

Here in the real world its various shades of gray on most of these points mentioned - if you don't have a lead role what do your junior engineers aspire to be the architect for which you have a handful of - or perhaps they're just looking for a job elsewhere.