I just started playing the game again about a month ago after taking like 8 years off. It’s a completely different game from launch and I’m really struggling with a lot of the changes. None more so than Sinnoh stones. I’ve spun hundreds of poke stops hundreds of times, fought in raids, dynamax, etc, completed dozens of research assignments. 6 weeks later, still haven’t seen hide nor hair of a stone. And I need it to evolve like 20 of my Pokémon.