Many hardcore WiFi evangelist seems to be in cribbing moods while associating WiFi with 5G. Or may be they want to hijack the buzz around 5G for wifi in this way, as WiFi has taken its own stride silently. WiFi is not 5G, damn clear is this fact, more than that only 5G NR is not 5G. WiFi is altogether different ecosystem, standards development etc. WiFi has been always relevant and deeply rooted in terms of internet access, also has got significant improvements in standards coping with time, 802.11 n, ac , ax. 5G emerged as utopian kind mobile technology, providing things what the different application want, with necessary capacity and efficiency. Therefore 5G comprises all the advancement in technological space, in computing and communication, like MIMO, Cloud, MEC, SDN, VNF etc. WiFi is one candidate there but a major one (complimentary) with advancement of 802.11ax, to achieve 5G objectives.
Infact we must understand that first standards of 5G through 3GPP release 15 was on 'Non Stand Alone', so called NSA mode. That's about taking 5G NR as associated radio in LTE control network. In true sense on LTE network with a data pipe of NR, Same could be done with any other radio, whether it be WiFi.
WiFi is much mature than NR, which is there taken for FWS only, WiFi has been there since ages as a synonyms of internet connectivity. So where comes a data pipe requirement WiFi is sufficient for multiple or many applications.
Also 5G is about use cases, a technology that will cater almost all the industry for connectivity point of view so akin to accommodate almost all the relevant radio technologies of caliber, we all are aware of some thing called network slicing, WiFi lies on prominent place there.
WiFi essentially a complimentary technology, in light of 5G, and to utter surprise it will be more prominent in 'Stand Alone", so called SA mode of 5G, where LTE will be out and it will be pure 5G network with SOA architectured 5G Core.