I’m assuming you attended school and were taught there.
Learning sight words works to a point. But you cannot memorise every single word in the English language. There are too many and it is hugely inefficient. For example, you could individually memorise the words sat, pin, pat, tap, pit, tip, tips, sits, tim, mat, mats, pats, pins, sit, spit. That’s 15 bits of information. And then you meet ‘pant’ and have no idea what it says. Or, you could learn the sounds that the letters SATPIN make (6 bits of information) and be able to work out all of those words plus any new ones you meet.
what happens with most children who are taught as you say you were, is that over time they work out the phonetic code for themselves by noticing patterns, and apply that to new words that they meet. Which is fine, and you say it worked for you, but the research suggests that most children (over 90% I believe) learn better by being taught the code rather than working it out for themselves. That’s why schools teach phonics - they tend to want to best for children and aren’t trying to trick them, as some on this thread seem to think.
Phonics is necessary because there will always be new words. If you read Harry Potter, it’s full of words you won’t read anywhere else. If you truly believe in sight words only and no phonics, you’d have to ask someone else how to say every new word you meet (eg muggle, Gringotts, Hogwarts, Griffindor). Most people are able to work out how these should be said - they can only do that by using phonics knowledge.