Yes. The last decade. Where nearly every game has some monetary hook involved beyond initial purchase.
There's no deterrent to moving or making a new CS game. Your two examples are heavy revenue drives for their respective companies. Valve is at least petty enough (and lazy enough) to want to maintain CSGO as-is, because even a single lost dollar is a missed opportunity to them. That's a whole other can of worms though and off-topic.
The thing about CS is that even if you split the entire playerbase in half, so long as Valve supported it how they supported CSGO, it'd regrow. Valve is a company capable of offsetting that cost, if you think CSGO is what makes them the most money you're delusional. There's no risk in them switching gears, putting out a new game, and then introducing new skins/weapons to that game. In fact, it's kind of sound strategy, since it'd allow them to experiment more, create a more modern visual experience, and they could still make money off the older platform's skins.
Everyone here thinks it's some huge, suicidal move, but Valve is in a position to pivot however they please. CS players just seem to think they're so special Valve will protect their interests. They won't. Their rationale will probably be "they'll buy new skins for a new game."