How important is PageSpeed ​​Insights loading speed?

Question

Google

Greetings)
I'm making a portfolio for myself .... I check the download speed by PageSpeed ​​Insights , for computers 97 , but for mobile 35-38 (although a month ago it was also more than 90 ). Compressed images, scripts, styles .....
Writes:
- Use modern image formats JPEG 2000, JPEG XR and WebP - but they are not supported by all browsers
- Eliminate display-blocking resources , i.e. css styles (they are included in the header)
- Adjust the appropriate size of the images , but they are not big anyway, 800x450px
-Set the rules for efficient use of the cache for static objects (Yandex maps)
How can this be fixed, or is it not so important ...? How do you deal with such situations? Do you follow google guidelines?
Thank you.

Answer 1

Use modern JPEG 2000, JPEG XR and WebP image formats

To do this, there is a picture tag with source, in which you can use webp. If not supported, then this source will not be used.
I advise you to read on critical-css, i.e. css which is required to display the first screen. The rest of the css can be included just at the bottom of the site.
but on mobile there are no such sizes. at best 375px and @2x, which corresponds to 750px, you need to load those image formats and sizes that will suit the current screen resolution, through the same above-mentioned source tag inside picture
Since we cannot influence the installation of the cache on the Yandex servers, you can use the lazy loading of Yandex maps, for example, a solution with a promise , which you will already run when the page is loaded. Or make a combo - initially we give a screenshot, and if you already need an interactive one, we load the scripts through a promise and render the map.
As stated, this is just a suggestion. To be guided by these recommendations or not, it's up to you to decide. However, Google has been using PageSpeedInsights data for a long time and takes it into account when ranking.

Answer 2

I try my best to optimize the site. Or rather, not myself, but my front-end worker, since I am engaged in back-end. I advise you to connect styles at the bottom of the site. You should use a web server for caching. Again, for images, I use programs like imageMagic so that the server issues exactly the file size that the user needs to the frontend.

Answer 3

Everything is the same as the first answer. Also puzzled now getting a high score from PageSpeedInsights. The assessment of the mobile version is strongly influenced by the presence of Y.cards. Therefore, I stupidly give static for mobile and interactive for desktop. And this already significantly raises the rating for the mobile version.
Placing only css for the start screen in the header also has a positive effect on the score.
These are the 2 main points that significantly change the size of the PageSpeedInsights score for the mobile version.
Plus lazy load of images, plus image resolution to fit the screen size, plus client and server caching.

Answer 4

https://habr.com/post/429668/
No more, don't worry too much. Or rather, the final value is still important, but now all these "compressions into optimized formats" have a very small weight, the main thing is how quickly the site loads. And that's it.

Answer 5

I think that the recent drop in mobile phone ratings in pageInsights is
due to the increasing influence of comparing indicators with AMP indicators
, apparently they are hinting to us, they say, connect turbo pages and all this rubbish
and don’t compost your brains with your html5 and bootstrap