Is iPhone 8 being throttled?

I recently got a new battery fir my iPhone 8. I checked my Battery Health & Charging in Settings and it says “Your battery is currently supporting normal peak performance.”

The Battery Maximum Capacity is 98%. But the performance is terrible. It lags terribly. Sometimes it almost seems to freeze. Does Apple throttle iPhone 8 even with a new battery? I know it’s old , and I do plan to upgrade next year. But it’s a perfectly good phone except for extremely sluggish performance. Thanks for any info.