Does the validation (quality) of the HTML code affect search results?

Question

HTML

Hello. Does the quality of the website's HTML code affect search results? And is it worth doing everything as the validator - https://validator.w3.org recommends ?
Examples:
1) I don't have headers 2) I style css through 3) I have deprecated html code. Instead of ; I use tag 4) I have a bug in the code PS No, I don't write code like that. But I want to understand for myself whether the quality of the HTML code and search results depend on it. <h1>, <h2>
<p style="font-size:22px;">
text-decoration: underline
<div style="clear: both";>

Answer 1

1) The absence of headers is more important from the point of view of structured information than from the point of view of the validator. By the way, the validator doesn't care if you have h1 and h2 or not. If we are not talking about section and article, and even then these will be notifications, not errors.
2) and 3) garbage in the code - more page weight, more time to load -> minus. But the validator again has nothing to do with it.
4) the browser will display the site crookedly - visitors will leave - behavioral factor -> minus.
The validity factor itself does not play an important role. But if you take two identical sites (in a vacuum), then the valid one will win.

Answer 2

yes, I won’t say for sure whether points 2 and 3 have an effect, but 1 and 4 definitely do. But for you to understand, they influence to some extent, not so that you will fix it all right now and immediately get into the top 10)

Answer 3

I will say this, of course, when ranking two similar sites, the PS in the sickle above will give out a more valid site, and you already draw your own conclusions ;-)