Why people really like to post their personal life on social media?

Why people really like to post their personal life on social media?
I know this is an endless question but Is it really necessary to let your personal life or private life be known by people who does not even know you? Or even if they do know you do you have to post everything?

Before social media even existed, people were more discreet about things and people do respect other people personal and private life, noone knew about other people personal life not even your own close relatives or family, unless you tell them in person (not oever a computer screen or if you found out over a social media site) if it was personal or private it says with you and only you and noone knew anything, so things or situation never back fire at you cause there was no proof of anything good or bad happened. Now with social media, noone respects anything. By being so public, things may back fire at you not only thieves can access to your data but also what you believe is harmless of what you post it may be risky and harmful to others.

Do people who post evertything on social media or almost anything really deep down believe , they want to FEEL important, Validated and drawn people to like you just beause it is the only way people may admire and like you you if you post everything on social media? I mean what other believes or think of you, is so important to you? Do you based your life based on what other people think of you?

For example people who post photos of almost anything happening in their lives? Photos of them eating , food photos, photos of them partying, photos of them vacationing with family or friends, photos of them being in love or with your SO, or photos of them showing off their bodies at the gym or working out (for me this is vanity) there are thousands of more examples but I can't mention them here cause they are endless examples. Before social media, noone knew if you were in love or not, or noone knew if you had travelled to other
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countries, noone knew if you were fat or thin, or what type of food were you eating at some restaurant, unless you tell them or they see you in person but it was not for public knowledge. Some people even post or write they they are bored? So?

A friend of mine post almsot everything of what they do in their free time on FB or even at work time too, like when she goes mountain bike riding and take photos of her posing. Most of my acquatainces have their social media privacy settings ON.
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, the reason people can see what thye post. Not every pàrt of your life needs to be public, you dont need to adversise your whole life, whether you are bored or happy or sad. I have another guy who I know and lives alone but he has to post everything when he feels the blues or when he is angry at something. so people pity him on social media. That is no good to do!!
Why people really like to post their personal life on social media?
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