Just wanted to follow up and close the loop on this issue.
After some help in another thread, I now understand why Premiere Pro 25.3 gave me serious playback lag while version 22.2 ran perfectly smooth on the exact same system and project.
It has to do with how newer versions of Premiere handle hardware decoding. My laptop has an NVIDIA MX150, which doesn’t support hardware H.264 or HEVC decoding or encoding. From what I've understood another thread reply:
My laptop (HP ENVY x360 with Intel i7-855
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