While there may not yet be a
lot of 3pp content for PF2, there is some. Go on over to
DriveThruRPG.com and search for PF2. There's a bit of stuff on there, and bound to be more.
I agree that PF2 isn't likely to be a strong competitor for DD5, but look at it another way. DD5 is growing the market as a whole, bringing new gamers into the hobby, making it more mainstream. Inevitably, some of those DD5 gamers will get tired of it (for a variety of resons) and want to try new things. PF2, along with the dozens of other second or third tier FRPGs, will certainly benefit from the market growth that DD5 brings along with it.
PF2 is a really solid alternative to DD5, offering a range of character options that DD5 doesn't. Some people will prefer simplicity and rules handwaving, others will prefer greater depth and rules-based framework. There is no reason they can't coexist. And from a purely business perspective, Paizo had pumped PF1 for all it was worth. They got new revenue streams with Starfinder, and now PF2 is in the mix. Will it be a strong second option behind DD5? Or will it be confined to niche markets like so many games in the past? I know folks who still play Chivalry and Sorcery or Ars Magica, but it's unlikely there's much revenue left in those old games, cool though they may have been in their heyday.
As far as licensing is concerned, Paizo's Compatibility Licence isn't particularly difficult to meet. A prospective author has to strip out any Golarion-based lore and a few other minor hoops and it's job done. So I don't think we can ascribe a dearth of content to licensing issues.