So i just learned aws elastic beanstalk (EBS, ECS, ALB, EC2, Amplify, S3, RDS, SQS)

Essentially i learned how to operate with aws to deploy a full stack web application with custom backend i built, with security and jwt token, certificate manager, ssl/tls to set up https and redirect from http, and react/angular/nextjs on frontend

All with custom CI/CD pipelines docker and other devops shit

But i still feel like im missing on A Lot of stuff regarding aws. I havent worked with Fargate for example and dont know how it works or when to use it, but i heard other devs use it

Can someone list me a number of things i as a dev should know more regarding aws?

New to AWS as well, but I might suggest you to look into Cloudwatch and its Metric system. It looks pretty good.

Also I think many aws services are for very specific use cases (blockchains, ai, ar/vr), you'll hardly need them if you stick on plain web dev.

Well yes, that's because there are literally 200+ AWS Sevices :p

From what I've experienced so far, I'd expect at least some basic knowledge and/or experience with the following for a more all-round developer (not sure what you're going for):
- Cloudwatch for logging & monitoring: very important to always know what's going on and why. Handy cost-saving tip: if you need metrics, first write the data to logs and afterwards parse them into a custom metric. Easily factor hundred monthly costs depending on the volume/granularity. Cloudwatch Insights is also nice
- IAM: everyone should know how to properly create fit-for-purpose roles with just enough permissions
- Lambda: used for a lot of pipelines in combination with other services for logic
- SQS+SNS fanout design
- AWS CDK: Infrastructure (and security!) as Code is definitely the way to go for stack definition
- If you need a web-socket: use the IoT Core
- StepFunctions+EventBridge: orchestrate decoupled event-driven architectures

But like @dmonkey said: many services are quite domain-specific. Just don't forget that services can be used for many more use cases than you'd expect (like my example of an IoT core as out-of-the-box websocket)