On this forum, there's a tendency to push people towards more RAM. It's an interesting question how much casual users need and how it has changed over time. If I remember correctly, in 1999 my iBook came with 2GB of memory. Pretty quickly, I felt it wasn't enough. I switched to Windows for a few years, then got a MB in 2011 and was surprised that it still came standard with 2GB. I maxed it out at 4GB, which ran beautifully through El Capitan. But with Sierra things took a slight turn for the worse. Maybe it was the 4GB of RAM no longer being enough to run it smoothly or just the software update not really being that compatible with a mid-2010 MB, having HD instead of SSD, or some other issue. The main problem on Sierra was an annoying lag every now and then when typing, both on the web and using Pages. I don't remember if High Sierra fixed it. Other than that, however, 4GB still ran it pretty well. I was still using it last week.
Based on my experience with 4GB, I would say, for a casual user who doesn't open more than a few tabs at a time, doesn't game, and doesn't multitask (other than, say, having Safari and Pages open at the same time), I think 8GB should be enough. When making recommendations on this forum, I think there is a tendency to assume that somebody buying a MBP is going to use it for heavy editing or some other intense work. But I suspect a lot of casual users will reject the MacBook as too small, the Air as not having a good enough screen, and choose an entry-level MBP.
