Text input fields in SupplierSelect do not support rich formatting, inline graphics and so on.
SupplierSelect is for comparing information about vendor's products and services, not their document formatting skills.
Formatted text uses much more bandwidth, slowing down all aspects of the site
Formatted text is more difficult to manipulate or search
RFP respondents can upload whatever files they wish as Response Attachments. These can include graphics files which may then be referenced in question text.
Where a Buyer wishes a vendor to include graphics (e.g. technical drawings) within a specific RFP question, they can create questions with any number of file upload fields.