That's an illussion big CAs want to sell. It's not true. Plenty of businesses use Let's Encrypt certificates. From a technical point of view there is no reason

That's an illussion big CAs want to sell. It's not true. Plenty of businesses use Let's Encrypt certificates. From a technical point of view there is no reason a business cannot use Let's Encrypt. The certificates provide exactly the same security. There is really no difference in the encryption you need for a "personal/hobbyist" site or a business site. Yeah, CAs still successfully convince some businesses to pay a premium, because they don't understand how TLS works. That mostly works because in "business terms" the price is still low.