GTMetrix vs GPSI - who to trust?

Question

Web development

With the recent and unexpected update of the Google Lighthouse algorithms and the departure from the Pingdom scene, a question arose:

1. GTMetrix/YSlow scores 96/92.
2. GPSI readings 41m/72d.

Is it worth it to bother and sharpen exactly to the requirements of Lighthouse? In this case, this is a very painstaking and tedious work, and there are doubts about its efficiency. The goal is to ensure normal ranking.

The question refers to real practice, if anyone has it.

Answer 1

The main thing is not to be completely sad.