I 100% guarantee you that eventually the $15 tier will have “limited” ads and then the upcoming $25 tier is ad free, rinse and repeat. It’s happened with cable, it’s happened with streaming, it’ll happen with YouTube.
Netflix increased their prices from $10/mo to $16/mo in 2011 and faced massive backlash with tech journalists praising Blockbuster and saying "Up until today, we loved Netflix":
https://www.wired.com/2011/07/netflix-price-hike-anger/
https://www.houstonpress.com/arts/hey-netflix-wtf-6368309
Today Netflix charges $15.50/mo. The price rises and falls every 2 years and we get the same whining every 2 years: https://flixed.io/netflix-price-hikes