It's not just spectrum, though. The core network is totally different than 5G SA or whatever 6G has. Maintaining all of that will eventually be considered not worth the trouble, and it'll be decommissioned. If anything decommissioning will be faster for LTE because unlike 2G/3G (which were needed because VoLTE support was flakely and had device whitelists) there isn't much point in keeping LTE around for legacy reasons.

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cowlevel an hour ago | parent [-]

What are the differences between 4G and 5G core networks?

	▲	gruez an hour ago \| parent [-]
		https://en.wikipedia.org/wiki/5G#Core_network_architecture Big enough that most carriers can't even launch 5G with its associated core network ("5G standalone"), and had to use the kludge of 5G + 4G core network ("5G non-standalone)