That's not how things work lol. It's the percentage difference that matters, not the Tflop number between them, as performance scales with resolution.
Whilst the difference between the XSX and PS5 may be a PS4's worth in Tflops, the reality is that 17% difference might lead to very small graphical or resolution differences that are most likely going to be fairly negligible, as there is such a thing as diminishing returns the further up the resolution scale you go. That is if devs choose resolution to take the hit over frame rate, which I'd imagine they would (similar to this gen with the PS4 Pro).
To clarify on why the differences are so much less this gen.
Performance:
The PS4 has 40% more computational power than the Xbox One (1.84 Tflops vs 1.31 Tflops).
The Series X has 17% more computational power than the PS5 (12 Tflops vs 10.28 Tflops)
In other words, the performance delta was far greater this gen than it will be next gen.
Clockspeed:
The Xbox One's GPU clocks were 6.6% faster than the PS4's (853 MHz vs 800 MHz).
The PS5's GPU clocks are 22% faster than the Series X's (2.23Ghz vs 1.825GHz).
The benefits of a higher clockspeed that some have discussed were less apparent at the start of this gen than they are with the PS5/XSX.
Storage:
Both the Xbox One and PS4 came with a standard 5400rpm HDD.
The PS5 has an 825GB SSD at 5.5 GB/s, whilst the XSX has a 1TB SSD at 2.4 GB/s, so the PS5's storage is around 129% faster.
So here the PS5 actually has a clear advantage, unlike with the Xbox One and PS4 that were a wash.
Memory:
The Xbox One has 8GB of DDR3 at 68.26 GB/s and just 32MB of eSRAM at 204 GB/s. The PS4 has 8GB of GDDR5 at 176.0 GB/s. In other words the PS4's 8GB's of ram was 158% faster than the XO's.
The Series X has 16GB of GDDR6, 10GB of which is at 560GB/s and 6GB of which is at 335GB/s, whilst the PS5 also has 16GB of GDDR6 the entirety of which is at 448GB/s. So the PS5's ram is 34% faster than 6GB's of the Series X's, whilst 10GB of the Series X's ram is 25% faster than the PS5's.
In other words, there isn't anywhere near the gulf in memory performance between the PS4/XO as there is with the PS5/XSX.
Ultimately, the performance gulf between the Xbox One and PS4 was much bigger, and unlike with the Xbox One which essentially had no performance advantages over the PS4 (hence people resorted to secret sauces like Cloud, dGPU etc that didn't actually have provable or scientific benefits), the PS5 actually has a couple of real and tangible advantages over the Xbox Series X, or areas where they're near enough matched.