I don't think the problem is one with the housemates... I think it might be one with the editing
(I know I say this a lot, LOL, but hear me out)
It does feel that in older series - and not really old series, you need only go as far back as BB13 - the highlights shows were a lot more reflective of the house dynamics as a whole... we got coverage and footage of mundane little interactions and people making jokes and getting to know each other, sharing stories about their pasts etc... the bedroom is usually where this all happened. Housemates in bed, chatting total nonsense.
Today... I don't know if it's just a coincedence but it does feel like all of the highlights are taken up by the most conflict-driven areas of the house: the kitchen, the diary room (usually on air in the living room, too) and the tasks. And what we have as 'light relief' inbetween all of the drama, gossipping and bitching is a bunch of "it's a knockout!" tasks that're really quite boring unless they provoke some moment of mad genius from a housemate they involve...because really, no task in recent memory has been any good... the last one I actively enjoyed was BB14's quarantine task but even that had to get a few gungings in... so as a result, it does feel more like the HLs are just 60% tension/bitching, 20% tasks, 10% showmance and 10% partying. There's no reality to the housemates any more, they're just characters in this long drawn-out clash.