It can seem overwhelming but it’s not that bad. I started SL right before 9.15 dropped as a fresh level 50 mage so I kind of experienced this situation. I probably averaged maybe 4 hours a day, a lot yes, but not what I consider no-life’ing it. It took me about 1 month before I got to around 235ish ilvl and felt mostly caught up. I did have about 150K gold from when I played legion, but that was it. I was starting level 50, no flying, and not knowing anything.
I felt that I played at a casual pace, but I did feel that I was strategic in how I played. My goal was to get caught up as quickly as possible while still exploring what the game had to offer. You have to get as much bang for your buck and do the things that will save the most time first. In my opinion that was getting flying and a good legendary power.
Yes, you feel that you are way behind everyone, but I just accepted it because I knew what I was getting into. The fact that people are constantly making alts also makes it easier. You find plenty of people that are a similar power level because of all the alts being made. If you look at the dungeons being listed it’s not like they are all 15 pluses. You still see plenty of lower level content being run.
It’s true there’s a lot to do for a brand new player but should that be a surprise? They are going through ALL the content of an expansion. If it could be done very quickly then that would mean there wasn’t very much content…which is something people think already.