pretty much.
as to source of inflation? the primary jumps were due to several exploits that took too long to patch and by that point credits were laundered so thoroughly, that taking them out of the economy would affect too many people that did NOT use the exploits. couple that with removal of several credit sinks as well as making heroic 2 missions in early/easier zones both relevant to high level players AND something that awards a very decent amount of credits on completion and you have the situation we have today.
but yeah, I'm currently sitting at 296 mil in my legacy vault (not sure how much my actual total is, though I tend not to keep more then 500k on any given alt because you are about to reach credit limit message is annoying, so maybe a few mill more across the alts?) while playing solo VERY casually
and when I say casually, I mean most days I just hop in, pick up daily login rewards, use a rep token - currently a seasonal one though I'm still not maxed out on solo space missions, so sometimes I might do that, gift some gifts to whatever companion I'm leveling which progresses both my daily seasonal points AND builds up to conquest rewards, while taking less then 5 minutes of my time - and log out. when I actualy play beyond that its either playing through story quests or running a few h2 here and there, maybe a solo dungeon if the mood strikes. how did I build up a third of a billion you ask. Mostly selling encryptions from conquest rewards with a side of occasional mat you get with tech fragments. because I'm too lazy to do much else