In a way it feels much more like the companions are tag-along this time around, to me. I think thats because within episodes I'm constantly dividing my attention between six or more characters, and the companion-specific scenes in the episode don't necessarily feel more significant - sometimes feel....more like slightly out of place lulls in the narrative than anything else. Not that I don't enjoy all of that. I think it's cool they're trying to build a network of relationships between them. But the relationships I'm REALLY interested in the most are those between the companions and the Doctor. That's always been my interest. And I'm used to those being explored in high-key, high-energy moments too. But feels like there's just not ENOUGH of them. Qualitatively or quantitatively? So it's a combination of factors.
The advantage of having just one companion is I suppose that the Doctor and that one companion must always circle back into each other's orbit, and their experiences can be easily ....balanced and made into a whole by the narrative? Every thing the one does has a direct effect on the other (narratively) and - it's also generally written that way - like there's a ribbon that stretches between them.
I guess I'm missing that feeling. We've always had a 'primary' companion in modern who and it's an adjustment. Not sure if this is just adjustment uncomfiness or actually a critique on what they could improve on. (Although please yes give me more one-on-one relationship building between Graham and the Doctor, Yasmin and the Doctor, Ryan and the Doctor. Give me those feels pls. Let them discover not just the universe, but HER.)
Edit: maybe it's also something to do with the all the close-ups - ironically. Cuts up all the responses and actually makes it harder to feel a triple ribbon network?