depends what you mean by a lot of people. r/churning is a relatively large sub (~282k members), and that's dedicated to a fairly aggressive form of the game.

as to whether it's worth it, depends how you value your time. I'm a fairly modest spender; I get about $150 in cashback rewards and $200+ from signup bonuses each year. I don't travel much, so it would be hard for me to break even on any points card with an annual fee. not a huge chunk of change, but a decent return on ~2 hours spent each year with an excel spreadsheet. there's not much month-to-month overhead if you use autopay and something like personal capital to track your finances.

The sapphire reserve has an annual fee of $550. Its not a card that makes sense for most people in my opinion, but if you can use its benefits (primarily travel benefits), it might pay for itself.

There are plenty of communities built around it such as The Points Guy, who has thousands of followers.

It all depends on what you want to get out of it. I don't make a living off points, but it's certainly been profitable for me as someone who pays off my cards in full every month. For reference, the signing bonus that was offered when I got the Sapphire Reserve (100K points, though it's been dropped since) was more than high enough to pay for my annual fee for the entire time I've had it so far, so everything I've paid for with points (which is thousands of dollars) has been pure profit.