Yeah, it's definitely not just you. The playing field has shifted hard in the last couple of years, and the margin for error for smaller accounts is basically zero now. i've been digging into this from the tracking side (GTM's my main playground), and what I keep seeing is a compounding problem - not just in auction dynamics, but in the data layer itself.
Here's the pattern I've noticed:
Attribution gets murky fast when you don't have a solid setup. If your conversion tracking isn't pixel-perfect (and most small businesses' isn't), Google's automated bidding starts chasing phantom signals. That's the main cause of that week-to-week inconsistency you mentioned - the algorithm has less quality data to work with, so it overcorrects constantly.
Niche focus is the only real defence. I've seen this again and again in Ahrefs and GSC audits - broad-match campaigns with generic terms are basically throwing money into a black hole now. The accounts that hold up are the ones laser-targeted to a specific problem or audience, often with offline conversion imports or enhanced conversions plugged in via GTM.
Screaming Frog can uncover structural issues that directly impact Quality Score. Slow landing pages, broken internal links, thin content - these all hammer your Ad Rank, and small businesses rarely have the resources to fix them fast.
so no, it's not your imagination. The room for sloppy setup shrank, and Google's not forgiving. But the guys winning are the ones who treat their analytics implementation as seriously as their ad copy.