The graphics are modern in BFA, and the legion 100-110 graphics are better than WOD where you are now. There are also several mechanical mounts you can get at 120, and you could solo farm Mirimon’s head from the Uldaar raid at 100. It’s only a 2% drop rate but one of my favorite mounts. Took me 49 tries, but I had an army of alts running it every week, and there is a shortcut I used on you tube.
The best mount site is Warcraftmounts dotcom it has every mount and where to get it. In regards to gold, if your desperate you can buy a token on the blizzard store for $20 and exchange it for about 108k gold. The price changes constantly. Google “WoW token price” to see the current exchange rate.
Lastly, you will make substantially more gold at 120 From multiple sources. They periodically have emmisaries that reward 4k gold and take less than 10 minutes (5-6 min if you have flying). If you have 12 level 120 characters, you would make 48k gold In just over an hour. So get leveling! You can also solo farm old raids for mount drops while making a substantial amount gold, vendoring all the purple gear you get. There are other ways too.
If you want to get to 120 faster and don’t care about reading quest text, get the popular addon “Azeroth auto pilot”. It puts a dynamic blinking green dotted line on yor mini map that navigates you to the most efficient path at all times while questing. The addon also picks up and turns in all quests instantly when you click an NPC once. There is a setting with the option of watching cut scenes or not. You should be questing in WOD until 100. I always read the story quests on my first time through but sometimes not side quests. Alts use AAP.