You can buy a Series X now and enjoy the different games that will come for it way before they release on Switch soft successor or full successor AND with much better settings. Seems easy to me. If I had the money, I'd buy a PS5 without hestitation.
My bet with The_Liquid_Laser: I think the Switch won't surpass the PS2 as the best selling system of all time. If it does, I'll play a game of a list that The_Liquid_Laser will provide, I will have to play it for 50 hours or complete it, whatever comes first.