I perfectly understand your point, and I was too lazy to elaborate mine.
PS3 was not in a very comfortable situation, as MS rushed a bit XBox360, releasing it 1 year before, I believe without "completing" all the test on the machine(The ring of death), in order to beat Sony on the head start. Now, even though 360 didn't sell extraordinary well the first year, it managed to establish a very good reputation, mostly in NA, and from the second year, it really started to shine with better multiplatform games VS PS3, and a very competitive price, much much lower than PS3; things were not going very well for Sony, it was last behind 360 and Wii, the king of casual gamers. Only with the release of PS3 Slim in September 2009, Sony started "to recover the lost ground", devs started to learn more the complex architecture, and multiplatform games finally were gradually on pair with the 360 counterpart and later on, even better in some cases. So, even considering the above mentioned problems, PS3 managed to take the lead in Europe and be second Worldwide at the end of its life cycle, while 360 the king in NA, and Wii 1st in the Global and Japan.
So I agree with you 100%, and my only "concern" is :"how much successfull PS5 will be at Launch?" Like PS4 ? More ? A lot more? Microscopically less ?
I would say more, just a guess.
We agree on PS5 launch then..., i don't think we are the only ones......