They will always be niches that certain people deem to be saturated, but that won't stop a determined entrepreneur from starting up a new venture.
If you went back to January 2007, the iPhone didn't have competition from Samsung's flagship touch-based phones or Google Pixel (because they didn't exist yet). This was a time when Nokia, Blackberry, Sony Ericsson etc were the dominant phone makers and Steve Jobs' original goal was to capture 10 million sales/year with the iPhone, out of the massive mobile phone market.
If you went back to January 2004, the Tesla didn't have competition from Ford, Porsche and any of the other ICE car makers that have now announced EV models in their line up. In fact, investors would consider you stupid for asking them to invest in a car company or even one that planned to use batteries because of how messed up the economics of EV production was at the time.
And my point is that, that is a weird way of looking at it, because _now_ it's also the easiest it'll ever be, what does it matter if it was easier in the past? The past is gone.
Grandfather was talking about how hard it was in the past, and i just commented on my experiences in the past. Of course looking at the past is not actionable, but I never intended to give actionable advice - just provide a comment
Also, saying it will be even harder in the future isnt exactly actionable or substantial advice either.