However, those provisions are made in order to ensure a good/fair access to anyone, and therefore to prevent a single user or single technology from overusing those bands which are meant to be shared. For that purpose, there are associated restrictions (in terms of power/EIRP, duty-cycle) and/or mandatory sharing approaches (Listen-before-talk, detect-and-avoid, etc.). In the case of Wi-Fi, CSMA/CA is a form of listen-before-talk.
Unfortunately, mobile technologies defined at 3GPP (GSM, HSPA, LTE, NR) are not designed to be used in such a way (i.e. they don't have any sharing mechanism such as LBT and they require _by design_ dedicated/licensed bands), which by the way implies some kind of specific coordination at the country borders where two operators are using the same channels... (you might look at ECC recommendation 15-01 for an example of PCI sharing).
LAA is a way to have an LTE carrier within the (shared) 5 GHz band, but it has to rely on an anchor carrier for signaling, which requires licensed spectrum. Multefire is a fully-unlicensed solution, but I doubt many UEs (smartphones) support it, and anyway because it must implement the same power limitations and LBT as wi-fi in order to comply with regulations I doubt it would be much better than wi-fi... (maybe it would in some specific case where deterministic QoS is important)
One more thing : keep in mind that a typical 3G/4G/5G macrocell site (e.g. around 65 dBm EIRP per carrier) is something very expensive : your mileage may vary but it can easily be around 100000 € / site when some construction is required.