You may want to have a look into the Nextcloud Polls-app (https://github.com/nextcloud/polls). A full-featured forms-app is not available at the moment, and is not in development.
Maybe you know somebody - or you want to develop this app yourself
I noted that it only allows binary (Yes/No) type of responses.
The only feature I am missing is that cannot responders add own text, answer open questions or multiple choices:
Just a shame that all these years later it still canāt automatically put the form data into a spreadsheet which is the killer feature of Google Forms
You can save the CSV in Nextcloud or you can download it. Also there are two kinds of result presentations in the app Forms. But maybe you like to write an issue.
But sadly that still doesnāt seem to be trying to implement actually putting form submissions directly into spreadsheet doc, just directly into a CSV file. Definitely the right direction, but still not really whatās need imho.