Time4Tea: This is the thing though: it wouldn't be a significant amount of work for them to release on Zoom Platform. They have no client, no API to support. There would be no coding work for them whatsoever. Zoom Platform makes it as easy as possible for devs to release their game - literally all they have to do is
give ZP the PC files they already have and they would do the rest. I mean, there is clear proof of that, given that Zoom have restored and released many older games by themselves, without any source access or assistance from the original developers.
This is why I find it so disappointing when I see smaller indie devs not giving a s*** about smaller stores like Zoom. Either they don't 'get' how easy they are making it for them or they are simply fricking lazy. I would expect smaller developers to have more sympathy with the smaller stores, and I will be reluctant to support any that won't.
About this I think the main problems are minimum balance to get the money and reliability of the store.
Most people buy games on steam so the developer know it will get to the minimum balance (100$) to get paid sooner or later, even really small games, on steam and of course know and trust steam.
While if the minimum balance is 250$ like for the humble bundle widget and the game only sell a few copies of the game there it could be years to get the money out of there.
And if a developer don't know zoom how can they trust it that he/she will get paid?
For itch you can get the money directly on your PayPal account or request to be paid later, but if you get the money directly you are responsible to pay VAT for each transaction in multiple countries (not easy at all).
And you also need to upload each time the update to multiple stores.
Not sure how zoom works for this but I can understand why some developers don't want to use small game stores. Not just that, I remember the zoom team here on gog for a game that I don't remember said that that game was not available anymore because the developer wanted to rise the price... I think something like this can scare small indie.
Still I think a developer should at least sell the game in their own website and a itch or a humble bundle widget should be used (itch if payments are handle by them only require a transaction to be 7 days old to be payout and it handle VAT so I think that's a good deal... For more popular games humble bundle widget can be good too, and if you got your games on humble bundle too (but you should be approved for that by humble bundle), not just widget, it should be easier to get paid) + steam.
Gog and Epic are "curated" store (whatever that means) so you don't really know if you can sell the game on gog or epic (while if you pay 100$ you can be sure that your game is on steam).
While zoom and other minor store are a big question mark for most people (and for developers).
There is also the Microsoft store that pay without a minimum balance and with only 25$ one time payments on pc... For developers I think that's a good deal but the store is a pain in the ass even for them for multiple reasons (not just the default drm), for example if your apps don't support windows 10 S (stupid version) you need to say it in the description or, if your app crash for that reason, they will refuse it by default. Windows 10 S is a real pain to support.
Finally there are play store, amazon store and apple store. The play store works like Microsoft store but better (25$ only once and no minimum balance), but you can avoid drm. Amazon app store is free to use but is a pain because your game need to work on fire device. Apple store need 99$ each year and force drm so it's the worst kind. Of course the last 3 are for mobile version of games.