You made a very good point here. I think it’s especially the seniors who have to learn to not jump automatically onto hard tasks but let juniors pick them and guide them by doing so. I’m still struggling to do so on a regular basis because thoughts like “I’ll have to fix the mess afterwards” or “I can do that in a fraction of time” are holding me often back. But most of the time the angst is unnecessary and things turn out to be pretty smooth. The better you as a senior explain stuff, the easier juniors can learn and most importantly I’ve learned to let juniors fail. That sounds harsh but sometimes it’s important to try out things and realize afterwards that it can’t work that way. It’s the job of a senior to oversee that the junior doesn’t waste a whole sprint by doing so ;)
I especially like your saying that most people are aware of issues just are struggling to talk about them. That’s very true and I think seniors can make a great contribution by starting those discussions. Speak out what went wrong, where you overzealously picked stuff and missed opportunities to help others. You’ll see that suddenly everybody speaks up.