Let me stop you right there. The PS5 launch line-up will be:
-> Miles Morales
-> Deathloop
-> Astro's Playroom and a bunch of indies/smaller second party stuff.
That's it. Sony is not going to pump out some huge first party games at launch because it would be stupid. They (a) don't like putting their first party stuff up against huge AAA third party games (Ass Creed, Cyberpunk), (b) people will buy the hardware off of hype alone, (c) in 2020 consumers don't choose which console to buy due to 'launch line-up' (that kind of thinking is our generation, not current generation) and (d) Sony will give its first party games release room to breathe for marketing and sales purposes (it's clear this is the smart strategy btw). Basically your thinking is stuck in 1995, not 2020.
There is going to be loads of stuff to play regardless - Spiderman, Deathloop, the huge third party games coming at the end of the year and the first party games this year on BC.
And the really GOOD news is that the first year is going to be wild - Spiderman, GT7, Horizon 2, TLOU MP. Demon Souls, Ratchet & Clank...and that's only the stuff we know about right now.
So basically to summarise:
(a) stop expecting a stacked launch line-up, there won't be one
(b) Sony is going all in the first year of PS5
(c) You might as well buy the console Christmas 2021.