I don't think the biggest problems are even with the grabs on income, although it's still bad (I'll come back to that). The worst thing is that under OGL 1.1 (and this was validated by a lawyer stream where he went through the doc line by line), WotC will be able to claim any content created under the licence as their own. Not just that - they could revoke the licence from a third-party creator and then do whatever they want with that content. So if an OGL business creates some new monsters that prove really popular, WotC could say "we think this is racist, we're revoking you're licence", even if it's nothing of the sort (the wording of the OGL is such that they wouldn't need to justify their stance), and then sell those monsters in their own products.
They could also revoke the rights of platforms such as Roll20 to support D&D games or OGL-based games, so that everyone has to use the new virtual tabletop coming to dndbeyond. It's insidious.
But yeah, the income thing. Note that they want 25% of any revenue over $750k. Not profit, revenue. If an OGL publisher like Kobold Press produces that level of revenue (which they probably do), most of the profits will go back into production. The developers who made Solasta use the OGL, so any future DLC or sequel they have in the works is going to be under serious threat, because as good as the game is, I don't expect it made huge profits. This is an industry with small profit margins, which means an attack on revenue will make a substantial number of businesses no longer viable. It'll kill them stone dead unless they're able to rapidly adapt and move away from the OGL, but even then, all their existing products will still be subject to the OGL.
There is an open letter which you can sign (I have) to let Hasbro and WotC know that this isn't acceptable:
https://www.opendnd.games/#open-letter
EDIT
Raid wrote: ↑Wed Jan 11, 2023 8:52 am
I have to wonder how much income the average player actually creates for them.
I was thinking about this last night. In our group, for example, I think Dave has bought some books (not sure if Alan has), but in my other group none of the players have ever given a penny to WotC as far as I know. I tend to buy most of the books for my own personal interest, which I suspect is the case for a lot of DMs because it makes sense that someone who enjoys reading RPG material would naturally end up wanting to run a game. In other words, I would say that in most groups - especially those which started since 5E was released - the DMs are the point of income for WotC, and I think that's something WotC / Hasbro have failed to appreciate.
I think that most groups are invested in playing some form of RPG, not necessarily D&D, and it's often the case that the group will simply play what the DM is happy to run. What this means in terms of monetising D&D is that subscriptions aren't necessarily the solution, because if the DM is pissed off with the situation (I certainly am) then they may end up just moving to another game, and then the players won't be paying any sub to WotC. Just to be clear, I'm not saying I want to move away from D&D.

But I do think this will backfire in ways they haven't considered if it goes ahead as the leaked doc currently stands.