There is a huge difference between not seeing adult children (especially not living at home) and not seeing children children who you normally live with FT though, it's just not a comparable situation IMO.
"It's really hard because although the household doesn't have to shield you have to isolate within the home if they don't, so use a separate bathroom, sleep in a separate room, eat separately, not be in the same room together etc etc."
Also this just isn't possible for some people, who don't have separate bathrooms or spare bedrooms. Lots
of people can't work from home as they work in factories or shops etc etc. Like everything, life is harder for people who are poorer. Especially true for shielding households.
I think that this situation is here to stay for the foreseeable, and the upcoming shielding "pause" is so people realise that this is not a sustainable strategy long term. I would be unable (logistically as well as emotionally) to live apart from my DC for many months let alone years. I also wouldn't expect them or my DH to dramatically reduce their own quality of life to protect me. (I know they would if I asked it but it's not fair). There is a tipping point between ensuring physical safety at the cost of emotional harm.
At some point we are going to have to accept that the risk to us personally is higher but that is how it is, sadly. We can change our own lives if we choose, eg avoiding any socialising at all etc but it's unreasonable to ask other people (especially the other people we love or live with!) to live that way when they don't have the same risk.
For the people we don't live with or love, the extremely clinically vulnerable are statistically such a small group, that sweeping restrictions to "protect the vulnerable" isn't fair or reasonable. (I think it's a bit like the the concept of "reasonable adjustments" in the Equality Act).
I think using "protect the vulnerable" to excuse the behaviour of a man who is not a good father normally (doesn't bother with contacting or seeing his DC) isn't right.