Global and the most normal - Media settings for WordPress?

Question

CMS

Please tell me what is the best and optimal image size for a website in 2019?

• Tell me who knows, and definitely understands this.
  

Give clear advice on what exactly should be:

1. The size of thumbnails, is it needed and why -?
2. Average size - is it needed and for what -?
3. Large size - is it needed and for what -?

- And in general, do you need to configure something in Settings-Media files or leave everything by default (150x150, 300x300, 1024x1024) or even put it everywhere - 0?
- And if, for example, I use some kind of image optimization plugin like Smush, do I need to make settings at all in "Settings-Media Files"?
- And in general, what should be the width and height of the image for the site in 2019, and indeed always, everywhere and in everything?
Please explain in as much detail as possible who knows, just nowhere, absolutely nowhere is there a clear answer.

Answer 1

Don't use plugins! Set all values ​​to 0.
And generate the required dimension using: https://www.binarymoon.co.uk/projects/timthumb/