It's tricky, isn't it. I have a nonogenarian mother to visit/stay overnight with regularly and a 'senior' lady who is secretive about her age whom I occasionally visit (children are far away) - I discovered at the weekend she is over 100!
But I'm not going to test to see if I have some infectious disease or another. If I'm unwell I won't visit (and they'll understand): I've adopted this approach since well before 2020. Work is more difficult. MTFU has been generally been my mantra unless too rotten, but I, and I suggest very many, will moderate and reduce the threshold of 'too sick to go into the office', especially if the mechanisms are in place to wfh without much reduction of efficiency. I think this point is worth employers and managers considering carefully: take a 'whole work population' approach. They (I) need to discourage MTFUers from bringing any lurgy in and spreading it.
I have a small stock of LFTs but struggling to envisage when I'd use one.