I'm waiting to get a PS5 until 2022 or 2023. Worst case scenario, probably in 2024.
I just got a PS4 in 2019, and it's a Pro at that. I also have a Switch. There's no games or features to draw me to the new consoles yet considering their price points (which are fantastic given the tech crammed into them).
I've got enough to play on my PS4 and Switch for a while, and even the occasional titles from older hardware as well.
Lifetime Sales Predictions
PS4: 130 mil (was 100 million) Xbox One: 55 mil (was 50 mil) Switch: 110 million (was 73, then 96 million)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima