I feel like just more app icons in general are blue than any other color. Off the top of my head in addition to what you mentioned I have shazam, venmo, signal, steam, blink, reolink, dropbox, steam, paypal, discord, max, disney plus. And that's not even counting one's that are majority white but with blue as the only color. I think it's just the most popular design choice or maybe there's some sinister market research somewhere that shows people use/spend more on apps that have blue icons.