

I send mail directly. I have a public IP address. I had to remove it (a few times) from a list of ‘dynamically residential address space’. I have configured the server carefully and implemented SPF, DKIM and DMARC. I have proper revDNS records. Currently my mail doesn’t seem to be considered SPAM by Google or others more often than other mails.
When filters consider some mail spam there usually is a reason. The trick is to find the reason and understand how to mitigate it. Some anti-spam measures are not fair (like blanket blocking whole countries or ISPs), but I was lucky enough not to be bothered by those.
In case of Stellaris it is more like you would buy Stellaris, Steallaris 2, Stellaris 3, etc. Each big DLC is like another game in the series. And the smaller ones (like species pack) are completely optional. For me this is an example of DLC done right.
It is not like e.g. City Skylines, that most DLCs just give some minor additions and for a meaningful change in the game you would have to buy lots of them.