Sitecore Forms prior to Sitecore XP 9.3 Initial Release do not support some components out of the box, such as File Upload and Captcha, which were available in the Web Forms for Marketers module. Users can create missing custom form elements by themselves.
Starting from Sitecore XP 9.3 Initial Release, Sitecore Forms support the File Upload functionality. It also provides the Bot Detection functionality that can potentially replace the Captcha functionality. To read more about Sitecore Forms and the Forms application, see the official documentation.