I´ve only bought one console at launch and that was the Dreamcast and I tend to keep it that way.
For the next generation, there is a couple of key things that has me signed up on the wait and see-approach.
Firstly, I always buy 1 or 2 year in because the games releasing on launch tend to suck ass. And in this day and age when a game takes a couple of hundred years to make I don´t see any point in day 1 buys since the generation doesn´t start before maybe 2 or 3 years in. I´m perfectly happy with cross-gen games that will inevitably take place yet again.
Secondly, the PS4 has still an incredible amount of momentum with several high profile games releasing this year and maybe next. It also has an impressive library of games as a whole, many of which I have yet to discover. As it feels right now, PS4 still has 3-4 years left in it for me.
Thirdly, the mid gen refresh that happened will probably happen again. I didn´t jump the gun because I don´t want to waste money on a another console when I already have one that is fully functional and plays all the games that I want without any compromises. It just seems dumb. So this time around I can wait for Sony to do a mid gen refresh of the PS5 and then buy that.
Forthly, my console of choice has to be backwards compat otherwise I don´t think I will bother, at least not until I feel I´m done with this generation. I´m getting tired of buying new hardware, gather a new collection of games and pack up the old collection of games in the drawer. A new generation also resets everything with features and what not gone from the face of the earth. The consoles are always bare bones when they are released.
Also, no fucking built in VR.