In general, cellular technologies have been designed against assumptions of a clean (or at least exclusively used) RF channel. 4G and 5G are deployed with frequency reuse between base stations, which implement the same standard and can coordinate their emissions and scheduling of clients (both in time and frequency) to minimise interference.

WiFi is a whole different kettle of fish - it's designed to be used by multiple independent access point operators simultaneously, with the ability to change frequency if needed based on the interference observed. It's designed to try to deliver good performance by listening before transmitting etc, to avoid transmitting over another device, to avoid a tragedy of the commons scenario where selfish devices end up rendering WiFi unusable for everyone (including themselves), through refusing to yield time to devices transmitting on other networks.

NR-U and LAA etc don't generally play according to the same rules, as they're standards arising from the world of exclusive spectrum access, and coordination of base stations by one operator - in the world of cellular, the base stations allocate uplink channels for their clients. That doesn't work in WiFi with multiple networks in the same approximate ___location, hence they need to try to prevent interference and cross-talk.