With AMD only having about 10% of the market and Nvidia refusing to even show AMDs cards in benchmarks I doubt they base pricing decisions on what AMD are doing.
The truth is that AMD are inconsequential and have little bearing on market pricing, Nvidia priced the 4000 series high because they had loads of 3000 series cards left over to sell so each 5000 series tier was made to look unattractive or offer no better and sometimes worse price to performance compared to the somewhat discounted 3000 models.
They definitely look at AMD when tiering their cards. The 3080 Super 12GB was sold in response to the 6800XT, as it slightly beat the 3080 in raster and had more VRAM.
Then you have the 3080 Ti which was sold due to the 6900XT being able to match 3090 at £500 less. The 3090 Ti was also released to counter the 6950XT which was beating 3090 in raster games.
If you look at 4000 series, we don't have 4080 Ti and 4090 Ti because AMD stopped competing in the high end. Usually near the end of the generation, Nvidia always releases x80 Ti to bring Titan performance at lower prices but the this time 4090 continues to be in a tier of its own. No variants compared to how it was with 3000 series.
5000 series will be even worse. They will heavily segment the 5090 performance like they did for 4090 and for 5080, it will offer 4090 performance for £1200, what should have been a 4080 Ti, this generation itself.