I am right there with you on all of this.
I'd like to see career mode go even further - make it a "Life of a Tour Pro" sim. You start as a high schooler, playing events on "muni-like" local courses. You do well, you get a scholarship and play at a university. You do really well, maybe you turn pro ASAP. Otherwise, you rise through the college ranks, play in the US Amateur, and eventually get onto the Korn Ferry Tour, then the PGA Tour.
Once you turn pro, you start to need to really take into account your winnings and sponsorships. You need to budget for things like your caddie, your transportation, your agent, etc. At first, with little money, you can perhaps only play in certain events that you can even afford to travel to. Your sponsors are smaller, less popular club manufacturers and apparel brands - let's say Ben Hogan and PGA Tour brand clothing. I know both Tiger 14 and PGA 2K21 have earnings and a money list, so being able to actually use this money would be great.
As you win more, bigger sponsors come calling - adidas, TaylorMade, Callaway, etc. You earn more money, can play a full schedule on Tour, and earn spots in bigger events. Eventually, you can hire better caddies that assist you in some way, and you could even be able to buy a fancy car, or a big house with a custom personal training facility where you play mini-games to enhance your skills.
I also think injuries could come into play, just like in other sports games. You get hurt, can maybe play thru it, but at a penalty to some of your skills and also with the risk of injuring yourself further.
I know I have derailed this, but tying back to Rory McIlroy PGA Tour - Rory's career mode was super barebones, so I hope EA can really flesh our their single player mode in their new game and give an experience that will be more than just "play and event, and then play another one".