Barbora Krejcikova is at her peak, she could be No. 1 by the end of 2023.
As for Iga, as a 21st Century baby, she has plenty of time. She was recently signed by Image Management Group, they tend to make athletes very rich with lucrative sponsorship deals. Iga isn't interested in chasing brands, she's seen what it did to Genie Bouchard and more recently Emma Raducanu. Genie failed to qualify for the AO, Emma is currently ranked 81st in the WTA. If she drops further, she'll need to qualify for Majors as well.