Bots have not affected me at all.

false. many thousands of low power bot accounts have drained reward pools for some time now, because a spellbook alone can get to like 1200 rating (possibly higher).

The problem isn't that bots exist, but that bots and players alike have been put into position where it's better to buy multiple $10 spellbook accounts than to buy/rent cards, only limited by the number of accounts they can manage (and tech-savvy people can manage quite a few more than normal players).

Personally I like the bots that buy/rent cards and actually play. Not as much the spellbook-only bots that infinitely farm the entire rewards pool from bronze by battling each other a million times only to turn around and sell 100% of everything they get because they don't need cards to farm rewards.

this change affects people proportional to how many accounts they have, which means the people abusing spellbook with 5000 bots suddenly need to reconsider their "dump everything" strategy