I've known a few beautiful people who are either not very nice or just terribly dull or really dim or have no sense of humour. Flat. One dimensional. Forgettable. You only have to watch a couple of series of Love Island to see that. Obviously on LI no-one is goes in looking less than 7 out of 10, but it's frequently not the most beautiful ones who are the most popular, on the Island itself or with the viewing public.
In the end, you are nothing without a decent personality even if you aren't especially clever. Being clever is an advantage, but people will forgive you for not being Brain of Britain if you are lovely and kind, wise, warm and funny. They won't forgive dull or spiteful or arrogant, no matter what you look like.
I've also known people who I found quite plain when I first met them, but after a bit of time in their company that all changed. Thinking of one woman in particular, she's not conventionally pretty, quite overweight, but she has a smile and a presence and a relentless positivity that lights up a room. She's witty and warm and funny but never too much. She's not loud, or fake or pantomime jolly, it's very natural and genuine. It's impossible to not feel happy when you are around her. She's like sunshine in human form and I find it hard to believe there can be a person on the planet who, if they knew her, would not feel the same. To me she's one of the most beautiful people ever and I can't even think about her without smiling. I even see her differently in physical sense now.
It's the same when you meet a bloke who you don't fancy at all at first, but once you get to know him and realise you are falling in love with fall in love his personality he starts to give you the uncontrollable fanny gallops.
Being beautiful is great, I imagine, but it's honestly not everything. It will get you so far, it will certainly open doors, literally and metaphorically, but in the end it probably won't save you from any of life's shit.
What people find off-putting is being around people who are relentlessly bitter or negative or pessimistic. Or people who have a persecution of victim complex. It's draining. So if my 'plain and fat' friend wanted to wallow and feel sorry for herself or constantly bang on about how everyone else was better looking than her then she'd be seen as that plain, fat woman first and foremost. As it is, no-one sees that past the first 20 minutes of knowing her. She has a really great job, legions of fans and a husband who adores her. I think there is a lesson there. There are certain things about ourselves we cannot change, but we can always choose to change our outlook on life.