I believe they are, but I haven't hunted for a best in soooo long.

I took a few years off. Could you explain a scanner please?

Nests are still a thing for sure! However, I don't think Silphroad still updates them, so you would kind of have to either stumble upon them, hear it from someone else or (what most ppl do) utilize a scanner.

Are nests still a thing? 

In the past if I wanted to catch Growlithe, I could search a nest, travel, and play. 

It seems now that they have changed the system? Silph Road is not updating with nests when I check it.  

Thanks for advice!

Nests & Silph Road