If you want to broke something in the 5ed the DM need to be in collusion.
Indeed - nothing about the system is broken, in holistic terms (i.e. not just small specific things the Moon Druid being OP or the BM Ranger being UP) there are just inflexible ways of playing it that self-limit the many options available.
If you want a high gold, high magic item game you can... easily... it takes little work. My current Greyhawk campaign is like that - everyone maxed out on attunements and rich enough to own a castle and several towns and villages. They fund wars, bribe guilds and use their gold in a way that makes the game richer and more like Game of Thrones where THEY are the players of the Great Game.
What's not to love!?
In my homebrew 'Bastion' campaign, almost the complete opposite is true. Much high magic is lost and magical items are as rare as rocking horse droppings and the characters are realistically poor. But hey, surprise, the game is equally playable and equally very easy to run.
I didn't even need to write anything down in terms of houserules - there was simply no need.
If you don't think the rules support your own style of play in these regards, then you probably need to revisit them and challenge any assumptions you think you see. I think some people read things into the rules, or don't focus on the GM flexibility design element of it being 'your game'.
It really is your game if you want it to be!
5th Edition is not 4th Edition, nor 3rd - as one of WoTC stated design goals, it harkens back to the days of 1st and 2nd Edition, when CR didn't exist, guidance on GM'ing was far scarcer and less rigid and creative flexibility within the rules was consequently greater.
I for one think that's great, and I applaud WoTC for making 5th Edition the way it is.
It is neither a problem, nor broken - and a few niggles aside, it's a great system.