iMac 11,2 (2010) with Radeon non metal GPU- Downgrade from Ventura or YOLO and install Sonoma?

I’m running Ventura on it, but it doesn’t just work quite like it should. Windows sometimes get laggy, YouTube and Netflix on Firefox will freeze, the Bluetooth air mouse doesn’t connect well at all. I was thinking about trying to downgrade to the last official supported OS (high sierra) to see if it runs better. Or, maybe it’s just old and won’t run well and might as well install Ventura? Any insight, seasoned iMac experts??