What facts to convey to the client in favor of adaptive layout?

Question

css

The question is to find clients to create\modify their sites in an adaptive layout. I think that in order to convince a client to order an adaptive layout , some weighty arguments are needed WHY it is for him , because often they do not understand the meaning, and if the site looks so good, then this is enough. Of course, there is a category that understands, and this is good news!
The following arguments come to mind:

• Search engines actively highlight and raise in the results sites that are adapted for mobile devices, and this is one of the main advantages.
  
• It is much more convenient for my potential client's clients to be on the site, which in turn can affect the conversion.
  
• ...nothing else comes to mind. Need your support!
  

Answer 1

Just show the customer sites without adaptive layout on a smartphone.

Answer 2

If the mobile version of the site looks terrible, it reflects badly on SEO.
Well, the percentage of visitors from smartphones is now very high, that's enough.

Answer 3

I would also say that you need to take into account the audience of the site. For example, an industrial-oriented audience has only recently seen a computer, and few of them have smartphones with a 5 "screen) So adaptation is needed, but not for everyone.