I agree with you on a lot of what you said...up to a few of these points.
To be honest, there is not that much in the way of licensed content in 2K21, at least compared to previous popular golf games.
There are only 16 licensed courses in the game (with the 16th being the recently added Detroit Golf Club). For comparison's sake, Tiger Woods 14 for PS3/X360 had 20 courses included in the standard game's disc, with 6 more available on-disc in the Masters Historic Edition, and 18 more available via DLC. And there's also the fact that TW 14 had all 4 majors licensed, where PGA 2K21 has zero.
And I know there are thousands of created courses out there, lots which are high-quality. But a PGA Tour-branded game needs as many real-life, licensed courses as it can. A total of 16 isn't enough in today's day and age, in my opinion. That's less than half the events in the career mode - why would I get excited about a PGA Tour mode when fewer than 50% of the events in it's season are played on fantasy courses?
TW 14 also had more licensed gear to use with your created golfer - more club options with more manufactures available (Cobra, Ping, etc.), more clothing and shoe brands (Nike is the big one...it is somehow licensed in PGA 2K21, but they don't offer any gear for your MyPlayer - it's just shown being worn by Tony Finau and Cameron Champ in career mode highlights), etc.
And when it comes to the "actively-developed" claim...there may be new content, but 2K is making their presence felt in this year's game big time. Any new content appears to be going in the game via the "Clubhouse Pass" method, which is simply a money grab.
In Season One of the Clubhouse Pass, only 20% of the reward levels are able to be unlocked for free. Putting 80% of the licensed stuff and other rewards behind a paywall, when licensed apparel and gear is a bit on the low side already, means you have to shell out real cash to get the most of the added content. And when the final Season One rewards include a shiny gold shirt and pants, as well as a putter in the shape of a flamingo...it makes it hard to really think these folks have their finger on the pulse of what people really want added to this game.
All that said, they did release Detroit Golf Club for free, which was a nice addition. Plus it came with all the Rocket Mortgage Classic presentation and the event was put into career mode replacing a fake one. So I will say there are positives.