Is learning VF development in 2021 still worth it? With aura and LWC in place especially the LWCs greatly supporting "anybody can code"? Would learning VF development be beneficial in 2021? Thoughts?
It depends on the job you have, or the job you want. Most new customers won't use Visualforce (most likely), but there are many, many thousands of jobs at companies that have orgs that are 5-10-15+ years old with a large number of Visualforce and other "legacy" code.
For example, we have hundreds of Visualforce pages (most that generate PDFs) that will take significant time to convert to an Apex-based solution. Apex-based PDF generation is still a bit annoying, as you have to query the records, generate the HTML, etc. Visualforce is still probably the easiest way to generate PDFs in most cases, anyways.
I would say that Visualforce will still remain viable for a number of years in the future. You need not be an expert at it, but you should still be casually knowledgeable about what Visualforce can and can't do, and basic syntax. Just going through the Visualforce Basics modules should give you everything you need to know for most use cases, and it's less than 3 hours of time invested.