Payload CMS

We are an NGO and we got from a partner a new design for our knowledge-sharing platform https://morethandigital.info/en/. We have now almost finalized the UI/UX Design in Figma with all the flows and functionalities for the future platform.

Next.js came up often as a possible solution for our future "platform" but I am not sure, also I found Payload CMS in the process as WordPress seems to be not the right decision for us. The next generation of our knowledge-sharing platform should also have more functionalities as the current version is only an article publishing platform.

Some of the new functionalities we thought of to make consuming/sharing knowledge easier:

• Better Author / Organization / Publication pages
• Peer-Review Feedback and Translation Feedback
• Translation flows and integration of machine translation suggestion
• Collaboration and live collaboration (like Google Docs)
• Follow Creators, Subscribe to Authors/Organizations
• Create collections (collections of articles) and share them
• As well as "Save for later" and other functionalities that help better interaction with content

As we are overwhelmed with the choices it is really hard to determine what technology stack/choices we should make in order to keep it as lean and easy as possible without creating too much overhead. Is there any "Best practice" you could recommend to allow for a low-cost development of our Design into a scalable infrastructure that doesn't cost thousands a month for hosting etc. (currently we serve 2.5 million people with 24 USD in Hosting and 20 USD in CDN with a WordPress system)? So please don't suggest options that are 100s of USD per month or thousands per month as we simply don't have the budget.

Any help/info/hints/recommendations are really appreciated!