A phone number is not necessary at all and a lot depends on the industry.
Recently, the address of the site is more and more often used instead.Modern business card puts on minimalism and simplicity - what my opinion makes a much better better impression than the old type of business cards.
Such stickers on the body or even paint the entire company car in advertising.
However, as everything can be overdone here too, so it is not worth refocusing the subject. Sometimes it's enough to use a simple sticker with the logo and phone number, which can be easily ordered from your local printing company.
Most of them also offer low advertising stickers, which can be useful in any company.
Multifunction devices offer increasingly larger scanning resolutions, less margin, larger formats, etc. But still, such home printers are far behind the professional equipment used in professional printers.Not to mention the much larger range of techniques used, which have nothing to do with those we know from home printers. Printed roll, solvent, water, anhydrous - long to exchange. The quality of such printouts is higher, which entails the obvious higher costs of printing itself. .