This is not intended to persuade you against using social media nor is it intended to be a formal / academic critique of social media. Rather, this is just a statement on the reasons why I personally choose against using social media in my day-to-day life, since I get this question a lot and feel it's a worthwhile subject!
The Social Dilemma popularized the concept that if one uses a service which they are not paying for, they are inherently the product. There are elements of this argument that I agree with and elements of the argument that I disagree with - but the premise of the argument is why I decided to forever give up my social media accounts on December 29, 2019 - an deliberately chosen date.
My aversion at the time was largely based on the idea that my attention was the product - that I was being shown advertisements and having my every move analyzed and thrown indefinitely into a database that I had no knowledge or control over. I considered it simply on the basis of pros and cons - the pros of social media at that time did not seem to outweigh the serious, albeit invisible, price that I had to "pay" as a user of the platforms. For example, an introduction to the price users of Facebook pay.
At the present moment, I do not disagree with the above notion in principle, but I do disagree with it being blindly applied to any circumstance. Rather, platforms which are owned by corporations or privately held will generally be well-described by the above, but decentralized, federated communities are not. Similarly, community initatives, whether free software or open-source, will generally not use their users as products.
When I learned of Mastodon, it excited me to see that there was a platform built in which users were most certainly not products. More recently, we've seen the advent of Bluesky - but Bluesky is backed by the interests of a corporate entity even if the servers are decentralized, while Mastodon is not. I have not personally reviewed the policies of Bluesky, so I can't make a recommendation about it from a standpoint of whether the users are being used as products.
If Mastodon is a social media service where the users are not products, then there is clearly something more to my reasoning than objections to the policies of the tech giants. This is where simple preference comes in. I have found that I feel healthier in the years since I abandoned being connected at all times.
When I used social media in the past, I found that it became easy for me to begin a session with a goal (e.g. looking at some posts of friends) and quickly lose focus, instead scrolling through endless feeds that were not what I originally set out to do. Much of this is largely due to the fact that I used platforms that were most certainly placing me in an intensely engaging filter bubble of content curated based off of my data - but it left quite a bad taste in my mouth.
None of this is to say that I am an anti-social person at all - quite the contrary, in fact! But I don't feel that I'm missing out by choosing against keeping in touch with others on social media. Much of what happens on social media seems to be less focused on the personal relationships that matter and more focused on trends, politics, news and interpretations, etc. In my life I want to engage with others in the most genuine ways possible, and, at least to me, it has seemed sustainable (and perhaps, even easier) to do so without the use of social media. So you won't find me on social media - only on this website :)