From a different perspective your sample size is just one, your team/company.

I started in a whole new team (as a senior) remotely during Covid which also contained juniors. They did incredibly well and were able to reach anyone remotely with no issue.

What might have been different is that the entire team was new and we knew we had to focus on our communication online and think about effective ways to do so. Which also benefited the juniors in the team. Many teams and companies never really gave it that much thought to begin with and I still see teams struggling to work remote at times. But, after giving them some pointers they often manage to do a whole lot better.

Some basic things out the top of my head that have benefited teams and juniors specifically:

- Have a "working together" channel where people can start meetings and where anyone can join if they feel like it. It often ends up being used by people who either like working together or those who can use some overall input on what they are working on. - Have social online moments as well. One team had a 15 minutes social block in front of standup's an other team had just a weekly social call. - Actively check in on other team members. Which feels silly to say, but the amount of times where I have seen teams only communicate during standup is also silly. Specifically juniors. If they are given a task after a little while check in with them how it is going and ask if they want to share their process. Basically how you probably in the office would walk past and also have a little conversation with them. - Take time for questions from juniors and make it clear you will do so. Whenever you are in the office and they approach you for help it means you also often serve them on the spot. Yet online I have seen juniors being ghosted for a variety of reasons. At the very least make sure to respond to juniors with a "give me 5 minutes and I'll give you a call".

To be clear, I personally like working hybrid and I do think there are benefits to coming to office at least for one day per week (assuming it is coordinated and not a ghost town). But my main point is that juniors struggling due to remote work is often more a symptom of the company not really having a good training and coaching process/culture in place more than anything else. Which I am not blaming on individual teams either. Training people is hard, people get bachelors degrees in education and then spend a lifetime getting better at educating. It's up to companies to educate their teams in this as well, offer the resources and have people on staff who solely focus on junior training.