And it could be the future in late 2030. Cause it has no any kind of Hardware's and other such setup.
I would not call master node a POW. It is more like a PoS system. You explicitly stated that you need to stake some coins so I don't understand why you assume it is a version of POW.
You also need to set up your own node (it is arguably cheaper, but still needs a setup), it is not a magical system where you can slap it anywhere and it will run perfectly. Not to mention you need to own some coins first, which might be costly depending on what coin you choose. The ROI also depends on the network and the price, if you choose a coin with a theoretically high ROI but the volume on the market is low, then you might not make a profit at all.
If you don't have an excellent budget to run your own mining rig, it is probably better to just buy some BTC regularly instead. Passive income sounds cool but usually requires some budget and luck. You can also look for farming on pools if you really want to get some interest, but remember that there is always a risk. Don't expect too much profit when you don't have a massive budget.
