To play piano in any key you will need to know a few more scales than learned in early lessons. Playing songs with chords is a very quick way to master the piano. You can play hundreds of songs with a few chords.
If you want to play songs in different keys because its too high to sing with keys you know. Possibly your friends can only play in one key that you don’t know. This is when knowing a lot of scales is imperative for you.
Jackie Clark who is a qualified piano teacher with over 25 years experience of piano teaching people of all ages and also composed all the music and also played in every single Honeycup Waters music video on YouTube.
Has created a course to increase your knowledge of scales. You can find out all about it with no commitment here