To me, if I have to spend any extra time figuring out how to spend those miles and points, or if I have to make even a single extra stop or adjust my itinerary to make use of them, then it is not worth it compared to a simple 2% cash back scheme.
Easily worth it IMHO. If I'm spending that money anyways, putting a bit of effort in to maximize the rewards seems logical.
What really happens is you hope you can do that but then get frustrated and either sit on your points for years or spend 2-3x the “optimal value” amount for something basic. Don’t get me wrong I like points, and it feels good cashing in on international business class tickets, but spending them in any way close to optimal is a stressful mess of transferring between airlines, calling service reps to get hidden seats and deals, gambling on upgrade availability, etc.
Finding great deals is not something accessible to someone who is only willing to spend 1-2 hours looking for a flight. You really do need to make it a hobby. I asked on r/awardtravel a few months back where all the deals were for an international flight I was trying to book 5 months in advance and got downvoted to oblivion because “everyone knows those deals are gone by now, you need to look at least 9 months in advance”.
With current interest rates of around 5%, one could get the same stream of income ($2.8k/y) by just plonking $50k or so into a high-yield savings account or money market fund.
To be honest, the $50k argument isn't comparable. It's like saying "Oh you have a side gig making $10k/year, why don't you just invest $200k in a money market fund instead?" First, someone could do both. And second, it's not even a logical comparison.
Of course there are airline/hotel specific cards and those may be more restrictive but I’ve never seen the point in those.
The one points card I have actually is a Marriott card which obviously only works with Marriott, but Marriott is everywhere and doesn't restrict scheduling options so it was an easy choice at the time. I used to travel weekly for work and the hotel was on me for reimbursement whereas the airline was on company card, and Marriott was the preferred booking option by my company so it made a lot of sense to get the card. The math at the time for that was like 5-7% when spending the points at Marriott plus a free night for what was an $85/year card. Useful for personal travel.
Might drop one of the two at some point though since they both cover the same niche.
I may waste my time on other things (like on hn, lol) but I don't think I want to spend it on that.