itch.io is fantastic for basically everything except the fact that the market is really small and fragmented, so you're almost always doing a lot of your own marketing and DriveThru does that better for indies, which is a little ironic.
With that said, DriveThru's cut is pretty big. It's more of a question of: Do I get a smaller fraction of a much larger flow, or do I go for a larger fraction of a lower flow? Itch.io makes PWYW a lot less obtrusive than DriveThru does, and DriveThru definitely has a better conversion rate for donations (in part perhaps because people like me always have some extra wallet credit from affiliate/publisher stuff).
For betas and stuff the reason I'm shying away from DriveThruRPG is that the interface to actually work with stuff on DriveThruRPG is a massive pain and I've found that it's very easy to mess up in ways that you don't want to mess stuff up. Almost all traffic on itch.io typically would be coming from outside, and that's not true for DriveThruRPG, but it is something that's almost 1:1.
I really do hope to do more freelancing. I've been enjoying it quite a bit. Portfolio work is nice; I've got a lot of writing under my belt but it's almost all self-published, and that doesn't look as cool as being able to say "I've written for X, Y, and Z."
In a real sense, however, in the RPG market outside of the Big Two, you're always doing a lot of your own marketing. DTR really doesn't do marketing well, which is an absolute shame and it's nice that they do it at all, but I've never – not once in many years – checked out any game because DTR promoted it. It always was promotion that originated outside of the sales platform.
Personally, I actually expect that you might have better luck focusing entirely on distribution through itch.io and not DTR. The bigger cut is nice, the loss in flow is a little annoying, but knowing upfront that you were going to be responsible for driving all of the flow put you into the right mindset for doing the necessary work. You are not the only person I have heard who is unhappy working with DTR as a distribution platform.
It doesn't hurt that itch.io has a fairly active (if small by comparison) social network of game developers. I haven't really dug into that group but I keep meaning to and hearing that they are a fine bunch. I've dealt with the people behind DTR and while I'm okay with having a business relationship with them if I must – I'd rather not. So I don't.
I want to be really clear that I am not busting on itch.io at all. I'm concerned that they don't have the traction that I would be comfortable with but when I look at the behavior of the market and at social media and at the evolution of the RPG industry as a whole, such as it is, it seems like there is a lot more to be gained by getting an early and being part of the community on itch.io the and it is being one of the hangers on with DTR.
Luckily for me, my particular field doesn't depend on the RPG industry except as a self-supporting hobby. Once upon a time, I almost fell into that trap but then came to my senses and said things like, "I like to eat and sleep indoors!"
(2020 prediction: Wait for the crazy blowback when itch.io starts being seen as the Epic Game Store to DTR's Steam. Does that make any sense? Absolutely not. Does that actually make it more likely? Yes.)