Platform choice matters mainly when it limits something the photography site genuinely needs to control. Squarespace, WordPress, and Wix can all support search visibility when important pages are indexable, page titles and descriptions are editable, images are handled sensibly, internal links are clear, and the site remains usable on mobile.
WordPress can offer extensive control because themes and plugins expose many technical settings. Squarespace and Wix can reduce setup complexity by handling more of the underlying site system. Neither approach is automatically better for rankings. The practical question is whether the current implementation lets you maintain accurate page metadata, useful service and portfolio pages, redirects, image attributes, structured data where appropriate, and acceptable performance.
Before considering a migration, audit the live site. Check whether you can edit the pages that matter, whether search engines can reach their content, whether gallery components render correctly, and whether the platform creates technical conflicts you cannot fix. If those controls are available, moving platforms solely for SEO may add risk without solving the real problem.
Choose a platform based on the photography workflow as well as search requirements. A portfolio site needs dependable image management, maintainable content editing, a clear enquiry path, and enough technical control to correct issues when they appear.