I hate to break it to you, but federated services are basically impossible to protect from scraping. The whole idea is openness and federation.
The only reason why places like Twitter and Reddit try to prevent scraping is so they can sell the data for profit.
If you post stuff publicly anywhere it will be scraped. On the fediverse it will be scraped via the open and federated APIs. On proprietary platforms it will be scraped via the proprietary paid APIs.