You haven't been doing it right
![Cool :cool: :cool:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
The only way it makes sense is if you DON'T spend more than you normally do and NEVER pay interest - your charges must be settled monthly. Which is not that different than paying cash for everything - except not actually carrying it in your pocket. Fairly easy if you're fiscally responsible adult. I assume we all are on this forum?
I have 15 cards right now (it changes periodically) and use them at different places depending on what benefits they offer. Amex Green gives me $10 off my phone bill, Chase Freedom pays 5pts/1$ spent at Amazon, Chase Reserve pays 10pts/1$ for Spotify and Netflix... etc. These are all purchases I make anyway - why not let banks sweeten the deal? Obviously this is not about $10 savings - I was doing it to fly in business and first class for peanuts (I won't say "free" since premium travel cards have annual fees) and stay in expensive hotels that I normally consider overpriced.
Last year I flew in JAL first class from NY to Tokyo for $5.56 and 72k AA miles and came back in business via Europe on Thai airlines and Lufthansa (maybe 80k Chase UR points?). In 2018 I went to HKG and SE Asia in Finnair business. A year before that, I was in South America... I still have 500k Chase UR points, 300k Amex MR points and 400k AA miles in my accounts. And my credit score (not that I care) is 820. Will those perks be worth anything if travel comes back? Who knows but accumulating these points didn't cost me anything...
It's a harmless hobby that actually creates value - unlike other hobbies that cost money - and it certainly doesn't prevent anyone from investing or creating wealth in any ways.