Communal accommodation in older people's flatlet schemes: useful, desirable?

Another pic of a flatlet scheme for older people; this is of the communal accommodation in one of the schemes I pictured yesterday. And it has an ad in the window for more residents, which marks out the block as accommodation for older people.

How useful is communal accommodation (a shared lounge): presumably it allows residents to build relationships in the scheme, and bring in others for meeting up, which in turn allows the living accommodation to be smaller. Is this what people want? Are they much used for either purpose? Do some places have organisers of activities, in which case does this move a flatlet scheme towards being more communal, like a care home