The club is absolutely huge.
I don't know how well-travelled you are, but they've probably got more fans in Thailand alone than Everton have around the world. Singapore, China, many other countries... they earn millions from fans who will never even step foot in England, whereas Everton can't even get a decent sponsor on the shirt and needed to roll back their morals to plaster Stake.com on the kit.
Notice how they travel to Asia every year to maintain their support over there? I was in Singapore a few years ago when they were coming and there was a frenzy in the country, red shirts all over the place.
They earn several times more for their training kit sponsor than we do for our main kit sponsor.
They have fans from around the globe going to Anfield spending hundreds on memorabilia.
Their reputation is that good that even crap players they no longer want are sold at a premium; Solanke, Ibe, Henderson, Fabinho, etc.
It's no surprise at all to me that they continue to be able to lash hundreds of millions on improving their squad.
Everton are decades behind them, maybe even three or four generations.