It is my opinion that IF you get baptized, you "join their club" and indicate that you are willing to obey their rules.
If you then break their rules, then,according to their rules, they can "disfellowship" you, at which point all the rule-following JWs will shun you.
For that reason it is best to avoid getting baptized!
The argument about people not having power over you could be said about almost any relationship. For example, long ago I had a job that involved a lot of daily travel. One winter we had a very rare and very heavy ice-storm and I decided that road conditions were dangerous, so I called my office and told them I was staying home that day, taking a "sick day." The next day when conditions had considerably improved, my District Manager called me out for not coming in to work and told me, "in the future, >I< will decide when it is not safe for you to come in to work. To myself I replied, "No, you will only decide if you will pay me for the day or not." The Manager sat in a warm, hazard-free office and drove a desk all day. He wasn't going to tell me to get in a wreck, maimed or killed at his whim.
There could have been negative consequences for me, in spite of the fact that I decided that >I< would control myself.
If you get baptized and the WTB&TS decides to disfellowsip you, you can't say, "No, I'm NOT disfellowshipped."
By the way, I got baptized 56 years ago when I was 14 because my mother and some elders TOLD ME it was time to get baptized. No one said a word about it being a "personal or private decision."
Years ago I coined the phrase (right here on this site) that baptism was the FIRST STEP in becoming an XJW.
Better still is it to never become a JW in the first place.