Where McDonnell is concerned I think there may well be some good explanation why the public don’t see him as much as previously, namely that he is more unpopular than the affable (seeming) Corbyn.
Firstly, who says we don't see much of McDonnell? You. But then you, as you have posted, don't read links or it appears watch political programmes. Those who are interested may or may not see more of him but you are not "we".
Additionally, you base this opinion on an ad hominin point "... he is more unpopular than the affable (seeming) Corbyn"., Ad hominems often signal the point at which a civil disagreement has descended into a “fight". This isn't a fight Lemongrove; it's a discussion, a debate.
If you would like to discuss how often different politicians appear, where they can be seen, on behalf of their party, please tell me how much you or "we" see of the Chancellor of the Exchequer who is actually a minister of government.