If you

understand what it is you’re replacing, what you’re replacing it with, and how to use the replacement

then you, almost by definition, are an advanced user.

A beginner should avoid these things, once you are far enough along to understand why you might want to replace one of these things, and form your own opinion on it, then go right ahead. But you’re no longer a beginner at that point.

Static IPs handed out by your local router are not dependent on having a static IP from your ISP. You do not need one to have the other. You can always have static IPs on your local network.

I took the title from the link, which doesn’t exactly match the title on the page. That’s why one says 20 years and the other says 15 years.